Question

What is an equation in point-slope form for the line perpendicular to y = 2x + 13 that contains (8,-4)?

Select one:
a. y+4= -1/(x-8)
b. x + 4 = 2(y - 8)
c.
y + 4 = 2(x-8)
d.
y+ 8 = -(x-4)

Answer 1

Point-slope form is y - y1 = m ( x - x1 ).

Based on just that, you can rule out B.

Since the point is (8,-4), we'd have:

y - (-4) = m ( x - 8)

This rules out D.

If we want our line to be perpendicular to y = 2x + 13, then we need to remember the slope of y = 2x + 13 is 2 and the perpendicular slope will be the opposite reciprocal: - 1/2.

Our line will be
`y+4 = -(1)/(2)(x-8)`.