## anonymous 3 years ago 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

1. anonymous

Do you need step by step help or just guidance?

2. anonymous

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

3. anonymous

would it be B

4. anonymous

Yes.

5. anonymous

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

6. anonymous

Ok, np.