Mathematics · essential
Angle between two lines using direction ratios for JEE
Direction ratios and direction cosines and the angle between two intersecting lines
Formula
\(\cos\theta=\frac{a_1a_2+b_1b_2+c_1c_2}{\sqrt{a_1^2+b_1^2+c_1^2}\sqrt{a_2^2+b_2^2+c_2^2}}\)
Variables: \((a_1,b_1,c_1)\) and \((a_2,b_2,c_2)\) are direction ratios of the two lines.
Most common JEE formula for angle between two lines.