💯 Maths

# How do you find the equation of a line PERPENDICULAR to y=4x+2? Verified
Moosa AliSavvy tutor and undergraduate at University College London (UCL)32 students helped

General equation of line y=mx+c 1. Find the gradient(m1) of the line. 2. Find the negative reciprocal(m2) of that: -1/m1(gradient) All lines with that negative reciprocal are perpendicular. (3.) If you want to find a particular perpendicular line, substitute, into general equation, the given (X, Y) coordinates and m2 (found in step 2), and use them to find c. This c will give you a unique equation. Verified
Ashwini PoopalDedicated tutor and undergraduate at Queen Mary University of London12 students helped

When you see perpendicular paired up with an equation of a line. Alarm bells should be ringing to you reminding you that it involves the negative reciprocal (-1/slope) The slope of y=4x+2 is 4 so the perpendicular line will have a slope of -1/4. Thé perpendicular line equation will be of the format y=-1/4x +b If you have the coordinate points you can then calculate b (which can be negative or positive)  