Why we don't normally teach chord, versine, coversine, haversine, exsecant, excosecant any more?
up vote
5
down vote
favorite
It seems that the following functions are not only excluded from a course in trigonometry, they are almost never taught in any course:
- Chord
- Versine
- Coversine
- Haversine
- Exsecant
- Excosecant
I could have asked the same question with the title "why have these functions lost their popularity" at math.stackexchange, but I fear that they will consider this question as "opinion-based".
trigonometry
asked 7 hours ago
Zuriel
58149
|
show 4 more comments
up vote
5
down vote
favorite
It seems that the following functions are not only excluded from a course in trigonometry, they are almost never taught in any course:
- Chord
- Versine
- Coversine
- Haversine
- Exsecant
- Excosecant
I could have asked the same question with the title "why have these functions lost their popularity" at math.stackexchange, but I fear that they will consider this question as "opinion-based".
trigonometry
asked 7 hours ago
Zuriel
58149
2
These things were useful when you had to look everything up in tables. But nowadays, with hand-held scientific calculators, we do not need them.
– Gerald Edgar
7 hours ago
@GeraldEdgar Even with the calculators, I bet almost all students don't even know what a versine is when they see it.
– Zuriel
7 hours ago
1
I don't teach these functions because I don't know what they are. I've heard of only half of them, but even for that half I'd need to look up their definitions. Students can look them up as well as I can.
– Andreas Blass
5 hours ago
1
On the one hand, you could get the answer from Wikipedia articles that you linked. On another hand, I learned something new, so thanks. Not sure why you included chord, which is not a trigonometric function, and is taught at school. As for "popular" functions, sine is useful when studying waves, cosine is useful to find a projection of a force, and tangent is the slope of tangent line, that is, a derivative. I guess finding a trajectory of a ballistic missile is more important nowadays than finding position of a brigantine.
– Rusty Core
3 hours ago
1
@PeterTaylor Thanks, fixed it
– Chris Cunningham
2 hours ago
|
show 4 more comments
up vote
5
down vote
favorite
up vote
5
down vote
favorite
It seems that the following functions are not only excluded from a course in trigonometry, they are almost never taught in any course:
- Chord
- Versine
- Coversine
- Haversine
- Exsecant
- Excosecant
I could have asked the same question with the title "why have these functions lost their popularity" at math.stackexchange, but I fear that they will consider this question as "opinion-based".
trigonometry
asked 7 hours ago
Zuriel
58149
It seems that the following functions are not only excluded from a course in trigonometry, they are almost never taught in any course:
- Chord
- Versine
- Coversine
- Haversine
- Exsecant
- Excosecant
I could have asked the same question with the title "why have these functions lost their popularity" at math.stackexchange, but I fear that they will consider this question as "opinion-based".
trigonometry
trigonometry
asked 7 hours ago
Zuriel
58149
asked 7 hours ago
Zuriel
58149
edited 1 hour ago
asked 7 hours ago
Zuriel
58149
asked 7 hours ago
Zuriel
58149
asked 7 hours ago
Zuriel
58149
58149
2
These things were useful when you had to look everything up in tables. But nowadays, with hand-held scientific calculators, we do not need them.
– Gerald Edgar
7 hours ago
@GeraldEdgar Even with the calculators, I bet almost all students don't even know what a versine is when they see it.
– Zuriel
7 hours ago
1
I don't teach these functions because I don't know what they are. I've heard of only half of them, but even for that half I'd need to look up their definitions. Students can look them up as well as I can.
– Andreas Blass
5 hours ago
1
On the one hand, you could get the answer from Wikipedia articles that you linked. On another hand, I learned something new, so thanks. Not sure why you included chord, which is not a trigonometric function, and is taught at school. As for "popular" functions, sine is useful when studying waves, cosine is useful to find a projection of a force, and tangent is the slope of tangent line, that is, a derivative. I guess finding a trajectory of a ballistic missile is more important nowadays than finding position of a brigantine.
– Rusty Core
3 hours ago
1
@PeterTaylor Thanks, fixed it
– Chris Cunningham
2 hours ago
|
show 4 more comments
2
These things were useful when you had to look everything up in tables. But nowadays, with hand-held scientific calculators, we do not need them.
– Gerald Edgar
7 hours ago
@GeraldEdgar Even with the calculators, I bet almost all students don't even know what a versine is when they see it.
– Zuriel
7 hours ago
1
I don't teach these functions because I don't know what they are. I've heard of only half of them, but even for that half I'd need to look up their definitions. Students can look them up as well as I can.
– Andreas Blass
5 hours ago
1
On the one hand, you could get the answer from Wikipedia articles that you linked. On another hand, I learned something new, so thanks. Not sure why you included chord, which is not a trigonometric function, and is taught at school. As for "popular" functions, sine is useful when studying waves, cosine is useful to find a projection of a force, and tangent is the slope of tangent line, that is, a derivative. I guess finding a trajectory of a ballistic missile is more important nowadays than finding position of a brigantine.
– Rusty Core
3 hours ago
1
@PeterTaylor Thanks, fixed it
– Chris Cunningham
2 hours ago
2
2
These things were useful when you had to look everything up in tables. But nowadays, with hand-held scientific calculators, we do not need them.
– Gerald Edgar
7 hours ago
These things were useful when you had to look everything up in tables. But nowadays, with hand-held scientific calculators, we do not need them.
– Gerald Edgar
7 hours ago
@GeraldEdgar Even with the calculators, I bet almost all students don't even know what a versine is when they see it.
– Zuriel
7 hours ago
@GeraldEdgar Even with the calculators, I bet almost all students don't even know what a versine is when they see it.
– Zuriel
7 hours ago
1
1
I don't teach these functions because I don't know what they are. I've heard of only half of them, but even for that half I'd need to look up their definitions. Students can look them up as well as I can.
– Andreas Blass
5 hours ago
I don't teach these functions because I don't know what they are. I've heard of only half of them, but even for that half I'd need to look up their definitions. Students can look them up as well as I can.
– Andreas Blass
5 hours ago
1
1
On the one hand, you could get the answer from Wikipedia articles that you linked. On another hand, I learned something new, so thanks. Not sure why you included chord, which is not a trigonometric function, and is taught at school. As for "popular" functions, sine is useful when studying waves, cosine is useful to find a projection of a force, and tangent is the slope of tangent line, that is, a derivative. I guess finding a trajectory of a ballistic missile is more important nowadays than finding position of a brigantine.
– Rusty Core
3 hours ago
On the one hand, you could get the answer from Wikipedia articles that you linked. On another hand, I learned something new, so thanks. Not sure why you included chord, which is not a trigonometric function, and is taught at school. As for "popular" functions, sine is useful when studying waves, cosine is useful to find a projection of a force, and tangent is the slope of tangent line, that is, a derivative. I guess finding a trajectory of a ballistic missile is more important nowadays than finding position of a brigantine.
– Rusty Core
3 hours ago
1
1
@PeterTaylor Thanks, fixed it
– Chris Cunningham
2 hours ago
@PeterTaylor Thanks, fixed it
– Chris Cunningham
2 hours ago
|
show 4 more comments
2 Answers
2
active
oldest
votes
up vote
6
down vote
More of a comment than an answer but: They are all composites of more basic functions. In fact, all of the trig functions could can expressed in terms of sine, linear changes in coordinates, and rational functions. For instance:
$$
tan(theta) = frac{sin(theta)}{sin( frac{pi}{2}-theta)}
$$
We certainly don't want children to have to memorize 20 different trig functions. That seems a bit silly. Do we even really need to teach all six ``standard'' trig function? Personally I tend to avoid $csc$ and $cot$ in my work...
answered 7 hours ago
Steven Gubkin
7,98512247
3
@Zuriel Indeed, that is the point. There is no mathematical need to teach them. The reason to teach them is because other people know them, and you don't want your students to be confused when they go to their physics classroom and their physics prof uses $cos$. However, the physics prof is probably not going to use the chord function so we can safely ignore it. Perhaps in a hundred years we will have abandoned $csc$. Good riddance I say. $cos$ and $tan$ have a special place in my heart however.
– Steven Gubkin
6 hours ago
3
There isn't a need for cosine in these other fields. I am just saying that the reason we use sine, cosine and tangent, but do not use versine, is the same reason that we use use glasses and don't use monocles: simply that monocles have gone out of fashion, and glasses have not. It is entirely for social reasons that we use some functions and not others. Your education must prepare you to have easy conversation with other people, so we must perpetuate some arbitrary choices to provide ease of communication. This is only one such choice.
– Steven Gubkin
6 hours ago
1
Other choices include the order of function composition, why we do not have a particular name for the antiderivative of sin(1+x^2), the order of operations, that $sqrt(x)$ denotes the positive number whose square is $x$, etc.
– Steven Gubkin
6 hours ago
2
Note that teaching students haversine, versine, etc will actually make it HARDER for them to communicate with others, because most other people have not learned these things. So they would have to find their common ground, and then work out the translations.
– Steven Gubkin
6 hours ago
2
In my heart, cosh and tanh are equally welcome.
– James S. Cook
4 hours ago
|
show 4 more comments
up vote
0
down vote
They are not rarely needed for applications problems in physics or engineering. Really sine, cosine and tangent are mostly what you need. Not even the co-functions.
I'm talking with respect to how formulas and problems are normally written in those courses. Ask yourself, did you encounter those functions in any of your science course and see a need for math to cover them as a service?
I think the versine and such are useful in navigation. But even for celestial nav as of post ww2, it was mostly done with tables and worksheets that don't require you to use these functions (or really know any of the math in what you do). I believe there was a time when there was more need for them before celestial nav became so work sheet oriented. And now celestial nav itself is a dying art because GPS is so common. Ask the average QM to use a sextant and see how he does...
answered 1 min ago
guest
112
New contributor
guest is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
add a comment |
2 Answers
2
active
oldest
votes
2 Answers
2
active
oldest
votes
active
oldest
votes
active
oldest
votes
up vote
6
down vote
More of a comment than an answer but: They are all composites of more basic functions. In fact, all of the trig functions could can expressed in terms of sine, linear changes in coordinates, and rational functions. For instance:
$$
tan(theta) = frac{sin(theta)}{sin( frac{pi}{2}-theta)}
$$
We certainly don't want children to have to memorize 20 different trig functions. That seems a bit silly. Do we even really need to teach all six ``standard'' trig function? Personally I tend to avoid $csc$ and $cot$ in my work...
answered 7 hours ago
Steven Gubkin
7,98512247
3
@Zuriel Indeed, that is the point. There is no mathematical need to teach them. The reason to teach them is because other people know them, and you don't want your students to be confused when they go to their physics classroom and their physics prof uses $cos$. However, the physics prof is probably not going to use the chord function so we can safely ignore it. Perhaps in a hundred years we will have abandoned $csc$. Good riddance I say. $cos$ and $tan$ have a special place in my heart however.
– Steven Gubkin
6 hours ago
3
There isn't a need for cosine in these other fields. I am just saying that the reason we use sine, cosine and tangent, but do not use versine, is the same reason that we use use glasses and don't use monocles: simply that monocles have gone out of fashion, and glasses have not. It is entirely for social reasons that we use some functions and not others. Your education must prepare you to have easy conversation with other people, so we must perpetuate some arbitrary choices to provide ease of communication. This is only one such choice.
– Steven Gubkin
6 hours ago
1
Other choices include the order of function composition, why we do not have a particular name for the antiderivative of sin(1+x^2), the order of operations, that $sqrt(x)$ denotes the positive number whose square is $x$, etc.
– Steven Gubkin
6 hours ago
2
Note that teaching students haversine, versine, etc will actually make it HARDER for them to communicate with others, because most other people have not learned these things. So they would have to find their common ground, and then work out the translations.
– Steven Gubkin
6 hours ago
2
In my heart, cosh and tanh are equally welcome.
– James S. Cook
4 hours ago
|
show 4 more comments
up vote
6
down vote
More of a comment than an answer but: They are all composites of more basic functions. In fact, all of the trig functions could can expressed in terms of sine, linear changes in coordinates, and rational functions. For instance:
$$
tan(theta) = frac{sin(theta)}{sin( frac{pi}{2}-theta)}
$$
We certainly don't want children to have to memorize 20 different trig functions. That seems a bit silly. Do we even really need to teach all six ``standard'' trig function? Personally I tend to avoid $csc$ and $cot$ in my work...
answered 7 hours ago
Steven Gubkin
7,98512247
3
@Zuriel Indeed, that is the point. There is no mathematical need to teach them. The reason to teach them is because other people know them, and you don't want your students to be confused when they go to their physics classroom and their physics prof uses $cos$. However, the physics prof is probably not going to use the chord function so we can safely ignore it. Perhaps in a hundred years we will have abandoned $csc$. Good riddance I say. $cos$ and $tan$ have a special place in my heart however.
– Steven Gubkin
6 hours ago
3
There isn't a need for cosine in these other fields. I am just saying that the reason we use sine, cosine and tangent, but do not use versine, is the same reason that we use use glasses and don't use monocles: simply that monocles have gone out of fashion, and glasses have not. It is entirely for social reasons that we use some functions and not others. Your education must prepare you to have easy conversation with other people, so we must perpetuate some arbitrary choices to provide ease of communication. This is only one such choice.
– Steven Gubkin
6 hours ago
1
Other choices include the order of function composition, why we do not have a particular name for the antiderivative of sin(1+x^2), the order of operations, that $sqrt(x)$ denotes the positive number whose square is $x$, etc.
– Steven Gubkin
6 hours ago
2
Note that teaching students haversine, versine, etc will actually make it HARDER for them to communicate with others, because most other people have not learned these things. So they would have to find their common ground, and then work out the translations.
– Steven Gubkin
6 hours ago
2
In my heart, cosh and tanh are equally welcome.
– James S. Cook
4 hours ago
|
show 4 more comments
up vote
6
down vote
up vote
6
down vote
More of a comment than an answer but: They are all composites of more basic functions. In fact, all of the trig functions could can expressed in terms of sine, linear changes in coordinates, and rational functions. For instance:
$$
tan(theta) = frac{sin(theta)}{sin( frac{pi}{2}-theta)}
$$
We certainly don't want children to have to memorize 20 different trig functions. That seems a bit silly. Do we even really need to teach all six ``standard'' trig function? Personally I tend to avoid $csc$ and $cot$ in my work...
answered 7 hours ago
Steven Gubkin
7,98512247
More of a comment than an answer but: They are all composites of more basic functions. In fact, all of the trig functions could can expressed in terms of sine, linear changes in coordinates, and rational functions. For instance:
$$
tan(theta) = frac{sin(theta)}{sin( frac{pi}{2}-theta)}
$$
We certainly don't want children to have to memorize 20 different trig functions. That seems a bit silly. Do we even really need to teach all six ``standard'' trig function? Personally I tend to avoid $csc$ and $cot$ in my work...
answered 7 hours ago
Steven Gubkin
7,98512247
answered 7 hours ago
Steven Gubkin
7,98512247
answered 7 hours ago
Steven Gubkin
7,98512247
answered 7 hours ago
Steven Gubkin
7,98512247
7,98512247
3
@Zuriel Indeed, that is the point. There is no mathematical need to teach them. The reason to teach them is because other people know them, and you don't want your students to be confused when they go to their physics classroom and their physics prof uses $cos$. However, the physics prof is probably not going to use the chord function so we can safely ignore it. Perhaps in a hundred years we will have abandoned $csc$. Good riddance I say. $cos$ and $tan$ have a special place in my heart however.
– Steven Gubkin
6 hours ago
3
There isn't a need for cosine in these other fields. I am just saying that the reason we use sine, cosine and tangent, but do not use versine, is the same reason that we use use glasses and don't use monocles: simply that monocles have gone out of fashion, and glasses have not. It is entirely for social reasons that we use some functions and not others. Your education must prepare you to have easy conversation with other people, so we must perpetuate some arbitrary choices to provide ease of communication. This is only one such choice.
– Steven Gubkin
6 hours ago
1
Other choices include the order of function composition, why we do not have a particular name for the antiderivative of sin(1+x^2), the order of operations, that $sqrt(x)$ denotes the positive number whose square is $x$, etc.
– Steven Gubkin
6 hours ago
2
Note that teaching students haversine, versine, etc will actually make it HARDER for them to communicate with others, because most other people have not learned these things. So they would have to find their common ground, and then work out the translations.
– Steven Gubkin
6 hours ago
2
In my heart, cosh and tanh are equally welcome.
– James S. Cook
4 hours ago
|
show 4 more comments
3
@Zuriel Indeed, that is the point. There is no mathematical need to teach them. The reason to teach them is because other people know them, and you don't want your students to be confused when they go to their physics classroom and their physics prof uses $cos$. However, the physics prof is probably not going to use the chord function so we can safely ignore it. Perhaps in a hundred years we will have abandoned $csc$. Good riddance I say. $cos$ and $tan$ have a special place in my heart however.
– Steven Gubkin
6 hours ago
3
There isn't a need for cosine in these other fields. I am just saying that the reason we use sine, cosine and tangent, but do not use versine, is the same reason that we use use glasses and don't use monocles: simply that monocles have gone out of fashion, and glasses have not. It is entirely for social reasons that we use some functions and not others. Your education must prepare you to have easy conversation with other people, so we must perpetuate some arbitrary choices to provide ease of communication. This is only one such choice.
– Steven Gubkin
6 hours ago
1
Other choices include the order of function composition, why we do not have a particular name for the antiderivative of sin(1+x^2), the order of operations, that $sqrt(x)$ denotes the positive number whose square is $x$, etc.
– Steven Gubkin
6 hours ago
2
Note that teaching students haversine, versine, etc will actually make it HARDER for them to communicate with others, because most other people have not learned these things. So they would have to find their common ground, and then work out the translations.
– Steven Gubkin
6 hours ago
2
In my heart, cosh and tanh are equally welcome.
– James S. Cook
4 hours ago
3
3
@Zuriel Indeed, that is the point. There is no mathematical need to teach them. The reason to teach them is because other people know them, and you don't want your students to be confused when they go to their physics classroom and their physics prof uses $cos$. However, the physics prof is probably not going to use the chord function so we can safely ignore it. Perhaps in a hundred years we will have abandoned $csc$. Good riddance I say. $cos$ and $tan$ have a special place in my heart however.
– Steven Gubkin
6 hours ago
@Zuriel Indeed, that is the point. There is no mathematical need to teach them. The reason to teach them is because other people know them, and you don't want your students to be confused when they go to their physics classroom and their physics prof uses $cos$. However, the physics prof is probably not going to use the chord function so we can safely ignore it. Perhaps in a hundred years we will have abandoned $csc$. Good riddance I say. $cos$ and $tan$ have a special place in my heart however.
– Steven Gubkin
6 hours ago
3
3
There isn't a need for cosine in these other fields. I am just saying that the reason we use sine, cosine and tangent, but do not use versine, is the same reason that we use use glasses and don't use monocles: simply that monocles have gone out of fashion, and glasses have not. It is entirely for social reasons that we use some functions and not others. Your education must prepare you to have easy conversation with other people, so we must perpetuate some arbitrary choices to provide ease of communication. This is only one such choice.
– Steven Gubkin
6 hours ago
There isn't a need for cosine in these other fields. I am just saying that the reason we use sine, cosine and tangent, but do not use versine, is the same reason that we use use glasses and don't use monocles: simply that monocles have gone out of fashion, and glasses have not. It is entirely for social reasons that we use some functions and not others. Your education must prepare you to have easy conversation with other people, so we must perpetuate some arbitrary choices to provide ease of communication. This is only one such choice.
– Steven Gubkin
6 hours ago
1
1
Other choices include the order of function composition, why we do not have a particular name for the antiderivative of sin(1+x^2), the order of operations, that $sqrt(x)$ denotes the positive number whose square is $x$, etc.
– Steven Gubkin
6 hours ago
Other choices include the order of function composition, why we do not have a particular name for the antiderivative of sin(1+x^2), the order of operations, that $sqrt(x)$ denotes the positive number whose square is $x$, etc.
– Steven Gubkin
6 hours ago
2
2
Note that teaching students haversine, versine, etc will actually make it HARDER for them to communicate with others, because most other people have not learned these things. So they would have to find their common ground, and then work out the translations.
– Steven Gubkin
6 hours ago
Note that teaching students haversine, versine, etc will actually make it HARDER for them to communicate with others, because most other people have not learned these things. So they would have to find their common ground, and then work out the translations.
– Steven Gubkin
6 hours ago
2
2
In my heart, cosh and tanh are equally welcome.
– James S. Cook
4 hours ago
In my heart, cosh and tanh are equally welcome.
– James S. Cook
4 hours ago
|
show 4 more comments
up vote
0
down vote
They are not rarely needed for applications problems in physics or engineering. Really sine, cosine and tangent are mostly what you need. Not even the co-functions.
I'm talking with respect to how formulas and problems are normally written in those courses. Ask yourself, did you encounter those functions in any of your science course and see a need for math to cover them as a service?
I think the versine and such are useful in navigation. But even for celestial nav as of post ww2, it was mostly done with tables and worksheets that don't require you to use these functions (or really know any of the math in what you do). I believe there was a time when there was more need for them before celestial nav became so work sheet oriented. And now celestial nav itself is a dying art because GPS is so common. Ask the average QM to use a sextant and see how he does...
answered 1 min ago
guest
112
New contributor
guest is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
add a comment |
up vote
0
down vote
They are not rarely needed for applications problems in physics or engineering. Really sine, cosine and tangent are mostly what you need. Not even the co-functions.
I'm talking with respect to how formulas and problems are normally written in those courses. Ask yourself, did you encounter those functions in any of your science course and see a need for math to cover them as a service?
I think the versine and such are useful in navigation. But even for celestial nav as of post ww2, it was mostly done with tables and worksheets that don't require you to use these functions (or really know any of the math in what you do). I believe there was a time when there was more need for them before celestial nav became so work sheet oriented. And now celestial nav itself is a dying art because GPS is so common. Ask the average QM to use a sextant and see how he does...
answered 1 min ago
guest
112
New contributor
guest is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
add a comment |
up vote
0
down vote
up vote
0
down vote
They are not rarely needed for applications problems in physics or engineering. Really sine, cosine and tangent are mostly what you need. Not even the co-functions.
I'm talking with respect to how formulas and problems are normally written in those courses. Ask yourself, did you encounter those functions in any of your science course and see a need for math to cover them as a service?
I think the versine and such are useful in navigation. But even for celestial nav as of post ww2, it was mostly done with tables and worksheets that don't require you to use these functions (or really know any of the math in what you do). I believe there was a time when there was more need for them before celestial nav became so work sheet oriented. And now celestial nav itself is a dying art because GPS is so common. Ask the average QM to use a sextant and see how he does...
answered 1 min ago
guest
112
New contributor
guest is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
They are not rarely needed for applications problems in physics or engineering. Really sine, cosine and tangent are mostly what you need. Not even the co-functions.
I'm talking with respect to how formulas and problems are normally written in those courses. Ask yourself, did you encounter those functions in any of your science course and see a need for math to cover them as a service?
I think the versine and such are useful in navigation. But even for celestial nav as of post ww2, it was mostly done with tables and worksheets that don't require you to use these functions (or really know any of the math in what you do). I believe there was a time when there was more need for them before celestial nav became so work sheet oriented. And now celestial nav itself is a dying art because GPS is so common. Ask the average QM to use a sextant and see how he does...
answered 1 min ago
guest
112
New contributor
guest is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
answered 1 min ago
guest
112
New contributor
guest is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
answered 1 min ago
guest
112
answered 1 min ago
guest
112
112
New contributor
guest is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
New contributor
guest is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
guest is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
add a comment |
add a comment |
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2
These things were useful when you had to look everything up in tables. But nowadays, with hand-held scientific calculators, we do not need them.
– Gerald Edgar
7 hours ago
@GeraldEdgar Even with the calculators, I bet almost all students don't even know what a versine is when they see it.
– Zuriel
7 hours ago
1
I don't teach these functions because I don't know what they are. I've heard of only half of them, but even for that half I'd need to look up their definitions. Students can look them up as well as I can.
– Andreas Blass
5 hours ago
1
On the one hand, you could get the answer from Wikipedia articles that you linked. On another hand, I learned something new, so thanks. Not sure why you included chord, which is not a trigonometric function, and is taught at school. As for "popular" functions, sine is useful when studying waves, cosine is useful to find a projection of a force, and tangent is the slope of tangent line, that is, a derivative. I guess finding a trajectory of a ballistic missile is more important nowadays than finding position of a brigantine.
– Rusty Core
3 hours ago
1
@PeterTaylor Thanks, fixed it
– Chris Cunningham
2 hours ago