Question

Solve the equation on the interval [0, 2π).
cos x + 2 cos x sin x = 0

A. 0 ; π/2 ; 7π/6 ; 3π/2
B. π/2 ; 7π/6 ; 3π/2 ; 11π/6
C. 7π/6 ; 11π/6 ; 2n
D. 7π/6 ; 11π/6

Answer 1

Do you need step by step help or just guidance?

Answer 2

\[\cos(x)(1+2\sin(x))=0\]
\[\cos(x)=0\implies x=\frac{\pi}{2},x=\frac{3\pi}{2}\]or
\[1+\sin(x)=0\implies \sin(x)=\frac{1}{2}\]etc

Answer 3

would it be B

Answer 4

Yes.

Answer 5

thank you very much. i just get stuck in the first steps.

Answer 6

Ok, np.