Browse Questions

# The angle between the lines whose direction cosines are $\bigg(\large\frac{\sqrt 3}{4},\frac{1}{4},\frac{\sqrt 3}{2}\bigg)$ and $\bigg(\large\frac{\sqrt 3}{4},\frac{1}{4},\frac{-\sqrt 3}{2} \bigg)$ is

$\begin {array} {1 1} (1)\;\pi & \quad (2)\;\frac{\pi}{2} \\ (3)\;\pi/3 & \quad (4)\; \pi/4 \end {array}$

$(3)\;\pi/3$