Question

What is the equation of a line, in slope intercept form, that is perpendicular to y=-0.25x+1 and passes through (2,5)?

Answer 1

Explanation:

Gradient of a line that is perpendicular to another line is always the negative reciprocal.

So:

the gradient perpendicular to -0.25x is 4

to find the y-intercept (c), you need to substitute x and y into the equation:

5 = 2(4) + c

5 = 8 + c

c = -3

hence:

y = 4x -3