Question

Solve the equation on the interval [0, 2π).

cos x + 2 cos x sin x = 0
A. pi/2, 7pi/6, 3pi/2

B. pi/2, 7pi/6, 3pi/2, 11pi/6

C. 7pi/6, 11pi/6 2π

Answer 1

Answer: -(sqrt 3/2)

Explanation:

Answer 2

`\cos x+2\cos x\sin x=\cos x(1+2\sin x)=0`


`\cos x=0` in the given interval when
`x=\frac\pi2,\frac{3\pi}2`.


`1+2\sin x=0\implies \sin x=-\frac12` when
`x=\frac{7\pi}6,\frac{11\pi}6`.