cos 11π/6 answer attempt 1 out of 5 cos 11π/6 =

Explanation:

Step1: Rewrite the angle

We know that $\frac{11\pi}{6}=2\pi-\frac{\pi}{6}$.

Step2: Use cosine property

Since $\cos(A - B)=\cos A\cos B+\sin A\sin B$, and $\cos(2\pi - \theta)=\cos\theta$, so $\cos\frac{11\pi}{6}=\cos(2\pi-\frac{\pi}{6})=\cos\frac{\pi}{6}$.

Step3: Recall cosine value

We know that $\cos\frac{\pi}{6}=\frac{\sqrt{3}}{2}$.

Answer:

$\frac{\sqrt{3}}{2}$