If [theta] is an acute angle with sin[theta]=3/5, find the exact value of cos2[theta].

This is the last one I am stumped on.

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- Apr 1st 2007, 03:17 AMgretchenAcute angle
If [theta] is an acute angle with sin[theta]=3/5, find the exact value of cos2[theta].

This is the last one I am stumped on. - Apr 1st 2007, 05:02 AMtopsquark
- Apr 2nd 2007, 09:31 AMjagabandhusome additional helps for you
You may use the formula to solve the questions related to this as

cos 2(theta)=cos^2 (theta) - sin^2 (theta)

= 1- 2*sin^2 (theta)

= 2*cos^2 (theta) - 1

These are the formulas to solve the problem