Unit Circle (Pre-Calculus) Question?

Question

Hi,

If anyone can help me understand this question I'd appreciated it. I need to

"Find the simplified exact value of:"

sin^2(-5pi/3)tan^2(pi/6) - cos^2(11pi/6)

Any help would be appreciated, thanks!

Answer 1

sin²(-5pi/3)tan²(pi/6) - cos²(11pi/6)
= sin²(pi/3)tan²(pi/6) - cos²(-pi/6)
= sin²(pi/3)tan²(pi/6) - cos²(pi/6)


= (√3/2)² * (1/√3)² - (√3/2)² = (3/4)(1/3) - (3/4) = -1/2

Answer 2

Hello,

Since pi = 180 we have
sin^2(-300)*tan^2(30) -cos^2(330) giving us 3/4*1/3 - 3/4 = 1/4 - 3/4 = -1/2


Hope This Helps!!