Question

The slope of a line is -4 and it’s y-intercept is (0,4) what is the equation of the line that is perpendicular to the first line and passes through (-8,2)

Answer 1

Original line equation: y=-4x+4

Perpendicular lines have opposite reciprocals, so the slope of the perpendicular line would be 1/4x.

Perpendicular line equation: y=1/4x+b

Plug in the coordinates that the line passes through to solve for b. Plug -8 in for x and 2 in for y.

2=1/4(-8)+b

Multiply.

2=-2+b

Add 2 to both sides.

4=b

Equation of the perpendicular line: y=1/4x+4

Hope this helps! :)