I recently read somewhere that , but I cannot seem to find this identity anywhere on the internet. Does anyone know what this is called, or where I can find the same identities (with x's and y's) for the other trig functions?

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- Dec 13th 2010, 07:31 PMbobbooeyTrig Identity?
I recently read somewhere that , but I cannot seem to find this identity anywhere on the internet. Does anyone know what this is called, or where I can find the same identities (with x's and y's) for the other trig functions?

- Dec 13th 2010, 07:33 PMProve It
You should know that .

So

. - Dec 13th 2010, 07:51 PMbobbooey
is it accurate to say that:

? - Dec 13th 2010, 07:54 PMProve It
- Dec 13th 2010, 09:24 PMSoroban
Hello, bobbooey!

Quote:

Take a look at where that equation comes from . . .

Code:`|`

| *

| * |

| h * |

| * | y

| * |

| * @ |

- - * - - - - - + - -

| x

We have angle in a right triangle.

The adjacent side is ; the opposite side is

Using Pythagorus, we find that: .

Therefore, we have:

. .