Write the slope-intercept form of the equation of the line perpendicular to the graph of y=-3/4x-7 that passes through (3, –2).

Question

Write the slope-intercept form of the equation of the line perpendicular

to the graph of y=-3/4x-7

that passes through (3, –2).

Answer 1

There are 2 ways to do this. Both involve the fact that perpendicular lines have opposite, reciprocal slopes.

1. y = mx + b

-2 = (4/3)(3) + b

-2 = 4 + b

b = -6

y = (4/3)x - 6

2. y - y₁ = m(x - x₁)

y - (-2) = (4/3)(x - 3)

y + 2 = (4/3)x - 4

y = (4/3)x - 6