Given: = with 90 < x < 180. Find: = So I actually did this: And simplified to: But this is not an answer choice. I feel like I have missed a step. Thank you.
Last edited by DaGr8Gatzby; Nov 30th 2009 at 06:23 PM.
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Originally Posted by DaGr8Gatzby Given: = with 90 < x < 180. Find: = So I actually did this: And simplified to: But this is not an answer choice. I feel like I have missed a step. Thank you. This makes no sense.
Edited: -1/6
Originally Posted by DaGr8Gatzby Edited: -1/6 It still makes no sense. What's X and what's meant to be done with X?
Maybe a screenshot would help: http://img694.imageshack.us/img694/9...91130at824.png Still stumped on this one.
Originally Posted by DaGr8Gatzby Maybe a screenshot would help: http://img694.imageshack.us/img694/9...91130at824.png Still stumped on this one. You are given where and asked to find . From the double angle formula: . Substitute and simplify: . and so the positive root is required: . Now rationalise the denominator. The correct option becomes obvious.
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