how do I evaluate cos^2 (95 degrees)

Question

I was assigned a math packet for an engineering class and I'm supposed to show work on all problems. Is there any handwritten way to solve this?

Answer 1

Another way is to use the trigonometric identity

 

cos²x = (1/2)[1 + cos(2x)]

 

cos²(95) = (1/2)[1 + cos(2*95)] = (1/2)(1 - 0.98480775) = 0.007596125

Answer 2

cos² 95 = (1 + cos 190) / 2

cos² 95 ≈ (1 + (-0.9848) / 2

cos² 95 ≈ 0.01519 / 2

cos² 95 ≈ 0.007596

Answer 3

Engineering!  First, find cos (95^o) = -0.0871557, to 7 DP

 

Second, square that number.  Answer:0. 007596 

Answer 4

cos²(95) = cos(95) * cos(95) = (-0.08716)  * (-0.08716) = 0.007596