how to evaluate cos13pi/6 and sin37pi/4?

Expert Answers

An illustration of the letter 'A' in a speech bubbles

We have to evaluate cos 13pi/6 and sin 37pi/4

Now cos (x+ 2*pi) = cos x

cos 13pi/6 = cos ( pi/6 + 2*pi) = cos (pi/6) = sqrt 3 / 2

sin (x + pi) = -sin x

sin ( 37*pi/4) = sin (36*pi/4 + pi/4) = sin (9*pi + pi/4)

=> sin ( 4*pi + Pi + pi/4)

=> -sin (pi/4)

=> -1/sqrt 2

cos 13pi/6  = sqrt 3/2 and sin 37pi/4 = -1/sqrt 2

See eNotes Ad-Free

Start your 48-hour free trial to get access to more than 30,000 additional guides and more than 350,000 Homework Help questions answered by our experts.

Get 48 Hours Free Access
Approved by eNotes Editorial