Verify cos (360 degrees -x) = cos

1. Verify cos (360 degrees -x) = cos

2. Verify that 7pi/6 is a solution to 2 sin2 x – sin x = 1.

Do the first part with you trig identities
cos (A - B) = cos (A) cos (B) + sin(A) sin(B)
cos (360 - x) = cos (360) cos (x) + sin(360)sin(x)
Cos (360 - x) = 1(cos(x) - 0 (sin(x) = cos (x)

Put in the value 7 pi/6 for x and work it out
and did you mean 2 sin^2(x) - sin (x) = 1 Shift 6 gives an arrow for exponent
2 sin^2(7 pi /6) - sin (7 pi/ 6) = 1
sin (7 pi/ 6) = - 1/2
2(-1/2)^2 - (-1/2) = 2(1/4) + 1/2 = 1/2 + 1/2 = 1

360-x = x