find exact value!!!!!!!!!!!!!!!!!!!!!!!!!!!!

Question

Find the exact values of sin(2theta)), cos((2theta), and tan(2theta), or the given value of theta

sec(theta)= -4; 90 degrees< theta< 180 degrees

Answer 1

Given that

sec(θ) = - 4 ⇒ 1/cos(θ) = - 4 ⇒ cos(θ) = - 1/4.

We know that

Cancel 8 from numerator and denominator

Cancel negitive symbols