(adsbygoogle = window.adsbygoogle || []).push({}); 1. The problem statement, all variables and given/known data

If sin x = 1/3 and sec y = 5/4, where x and y lie between 0 and pi/2, evaluate the expression.

sin2y

cos2y

2. Relevant equations

2siny = 2siny*cosy?

cos2y = cos^2 y - sin^2 y?

3. The attempt at a solution

I think sin2y goes to 2siny*cosy. I know what sin x is but how do I find sin y? The answer should be 24/25 for siny, but not sure how to get it. Not sure what the answer is or how to get it for cos2y.

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# Homework Help: Trigonometry help

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