Question

What is the equation of the line, in slope-intercept form, that passes through the point (4, -1) and is perpendicular to the line whose equation is 2x - y - 7 = 0?

Answer 1

To get the perpendicular we swap the coefficients on x and y, negating one of them. We get the constant by considering the line goes through (4,-1).

Original line:

2x - y - 7 = 0

Perpendicular through (4,-1)

x +2y = 4 + 2(-1) = 2

2y = -x + 2

y = -(1/2)x + 1

Answer: y = -(1/2)x + 1