Question

What’s the answer? I need help please

Answer 1

Answer: C

Explanation:

Think of a unit circle

sin x = -1/2 happens at 7
`\pi`/6 and 11
`\pi`/6, 3rd and 4th quadrant

Out of those 2 quadrants cos x is negative in the 3rd quadrant

So cos x= -√3/2

Answer 2

-√3/2

Explanation:

sin(x) is equal to 1/2 when x=7π/6 or 11π/6

cos(7π/6) = -√3/2

cos(11π/6) = √3/2

In the question, it says that cos(x) is <0, which means that it has to be negative

So, the answer is -√3/2