Question

Find the equations of a line that passes through (4,2) and is parallel and perpendicular to the line whose

equation is y = 2x - 4.
Parallel line:
Perpendicular line:

Answer 1

Explanation:

Parallel lines have the same slope as the reference line. The reference here is:

y = 2x - 4

This is in standard form of y=mx+b, where m is the slope and b is the y-intercept (the value of y when x=0).

m, slope, is 2. The new line will have the same slope: c

Now all we need is b, the y-intercept. We can find that byu entering the given point (4,2), and solving for b.

y = 2x + b

2 = 2*4 + b

b = -6

The equation is y = 2x - 6

See the attached graph.