Question

What is an equation of the line that passes through the point (2, 4) and is perpendicular to the line x -

y = 4?

Answer 1

y = -x + 6

Explanation:

Perpendicular lines have opposite reciprocal slopes.

x - y = 4

Change to slope intercept form

y = x - 4

so, the opposite reciprocal of 1 is -1

Now, let's find the y-intercept by plugging-in the coordinates where it passes

(2,4)

y = mx + b

4 = -1(2) + b

4 = -2 + b

6 = b

∴ The equation perpendicular to x - y = 4 or y = x - 4 is

y = -x + 6