For each of the following draw the reference angle and find the exact function value.

Question

a) cos(-330degrees)

 

b) sin(3pi/4)

Answer 1

Hi Paula,

 

a) The reference angle for -330° is 30 deg

 

cos(-330°) = cos(30°) = √3 / 2

 

b) The reference angle for 3pi/4 is pi/4.

sin(3pi/4) = sin pi/4 = √2 / 2