Draw a right angled triangle.

Let theta be an angle, 1 will be the opposite side, and 3 will be the hypotenuse.

Can you find the adjacent side through Pythagoras' Theorem?

Then, cos of theta is adj/hyp.

You should get the answer

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- April 11th 2011, 10:46 AM #1

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## sin(x)=1/3. What is cos(x?)

Given that , how does one find the exact value of without using a calculator?

The answer is supposed to be , but I don't see how one reaches it. I know the standard sine/cosine angles ( ...) and their corresponding Cartesian coordinates on the unit circle; is the result supposed to be derived from these? If so, how?

- April 11th 2011, 11:09 AM #2

- April 11th 2011, 11:19 AM #3

- April 11th 2011, 11:19 AM #4

- April 11th 2011, 11:21 AM #5

- April 11th 2011, 11:21 AM #6

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- April 11th 2011, 11:46 AM #7

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