Find θ, if cos θ = $-\frac{\sqrt{3}}{2}.$

$\frac{3π}{2}$ $\frac{5π}{6}$ $\frac{2π}{3}$ $\frac{4π}{3}$

$\frac{5π}{6}$

cos θ = $-\frac{\sqrt{3}}{2}$ { we know, cos 30 º= $\frac{\sqrt{3}}{2}$ } 30º= \(\frac{π}{6}\) cos is negative that means it lies in 2nd quadrant . So,  θ = π - \(\frac{π}{6}\) = \(\frac{5π}{6}\)