DavidP

01-14-2002, 09:34 PM

Okay....I have a couple questions about trigonometry functions...

Now, we probably all know the acronym:

SOHCAHTOA

which is short for:

sin = opp / hyp

cos = adj / hyp

tan = opp / adj

However, I have been wondering what exactly goes on inside of the sin(), etc. functions in math.h.

In the those functions, you only give the angle measurement, you dont give any opposite or hypotenuse side lengths....so exactly WHAT IS the math that it uses to figure out the sin, cos, tan, etc?

Its the same way with calculators...you give them angle measurements....so WHAT MATH do they use to figure out the answers?

I was talking about this to one of my friends...and one way is to automatically assume that one angle is 90 deg, then there is the user given angle, and then the 3rd angle is 180 minus those 2 angles. With three angles given, you can figure out the side lengths, and then figure out the answers to the trig functions.

However, it would be pretty hard to do this, because you could give ALL SORTS of different angles as input. Therefore if they DID do this, they could not simply use a matrix to store all the side lengths.

They could use some type of algotrithm...but how would they do that? What would be the math involved there?

So it all comes down to...what the heck goes on inside the trigonometry functions?????!??!?!????!?!??!? THEY DONT TELL US IN SCHOOL!!! and it makes me freakin angry because THATS what I want to know....

On a side note, I was also talking to one of my friends about how several teachers talk about using the guess and check system in certain instances. For example, factoring.

Why would anybody in the world want to use factoring, when they could just use the quadratic formula? Factoring requires the guess and check system in SEVERAL cases, and therefore, as a programmer, I consider that hard coding. However, using the quadratic formula, you just plug variables into a function and it returns a value. Much easier and more efficient. Not hard coded. So why the heck is guess and check (and factoring for that matter) even PART of curriculum in math courses?

Now, we probably all know the acronym:

SOHCAHTOA

which is short for:

sin = opp / hyp

cos = adj / hyp

tan = opp / adj

However, I have been wondering what exactly goes on inside of the sin(), etc. functions in math.h.

In the those functions, you only give the angle measurement, you dont give any opposite or hypotenuse side lengths....so exactly WHAT IS the math that it uses to figure out the sin, cos, tan, etc?

Its the same way with calculators...you give them angle measurements....so WHAT MATH do they use to figure out the answers?

I was talking about this to one of my friends...and one way is to automatically assume that one angle is 90 deg, then there is the user given angle, and then the 3rd angle is 180 minus those 2 angles. With three angles given, you can figure out the side lengths, and then figure out the answers to the trig functions.

However, it would be pretty hard to do this, because you could give ALL SORTS of different angles as input. Therefore if they DID do this, they could not simply use a matrix to store all the side lengths.

They could use some type of algotrithm...but how would they do that? What would be the math involved there?

So it all comes down to...what the heck goes on inside the trigonometry functions?????!??!?!????!?!??!? THEY DONT TELL US IN SCHOOL!!! and it makes me freakin angry because THATS what I want to know....

On a side note, I was also talking to one of my friends about how several teachers talk about using the guess and check system in certain instances. For example, factoring.

Why would anybody in the world want to use factoring, when they could just use the quadratic formula? Factoring requires the guess and check system in SEVERAL cases, and therefore, as a programmer, I consider that hard coding. However, using the quadratic formula, you just plug variables into a function and it returns a value. Much easier and more efficient. Not hard coded. So why the heck is guess and check (and factoring for that matter) even PART of curriculum in math courses?