Question

What is an equation for the line perpendicular to y = 3x – 1 that passes through (-9, -2)?

Answer 1

• y = -1/3x - 5

Explanation:

Perpendicular lines have negative reciprocal slopes, so the line is:

• y = -1/3x + b

Finding the value of b, using the given point (-9, -2)

• -2 = -1/3*(-9) + b
• -2 = 3 + b
• b = -2 - 3
• b = -5

The line is

• y = -1/3x - 5