How do I write the equation of a line that is perpendicular to y=3x+4 and goes through the point (3,5)?

1 Answer
Nov 21, 2015

y=13x+6

Explanation:

Two perpendicular lines have opposite reciprocal slopes.

The slope in y=3x+4 is 3, so the line perpendicular to it will have a slope of 13.

We can write this in the form y=13x+b and then plug in (3,5) for x and y to find the equation of the line perpendicular to the line y=3x+4 that goes through the point (3,5).

5=13(3)+b
5=1+b
6=b

Therefore, the equation of our new line is: y=13x+6.