given cos2y = 2 - sec^2(y)/sec^2(y) verify that each equation is an identity my mind is very boggling right now so please can anyone help with the steps?
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start with this double-angle identity ... $\displaystyle cos(2\theta) = 2\cos^2\theta - 1$
i am sorry but i'm still stuck because i dont know what to do from there on, i've tried different identities but i don't think its leading to the right one.
$\displaystyle \frac{2 - \sec^2{y}}{\sec^2{y}} =$ $\displaystyle \frac{2}{\sec^2{y}} - \frac{\sec^2{y}}{\sec^2{y}} =$ $\displaystyle 2\cos^2{y} - 1$
oohh..haha i guess i was thinking too hard and missed the simple steps.. thanks you very much
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