# 1 - Straight lines Questions Answers

show that line perpendicular to x-axis and a line perpendecular to y-axis having slope multipication -1

**Asked By: HARISH**

is this question helpfull: 13 1

**submit your answer****Joshi sir comment**

Angle between two lines is given by the formula

tanθ = (m_{1}-m_{2})/(1+m_{1}m_{2})

solve this by taking θ = 90