Question

A circle with the center C (4, -2) contains the point D (8,1). What is the equation of the line perpendicular to the radius of the circle passing through point C?

Answer 1

y = -4x/3 + 10/3

Explanation:

We find the slope of CD and get (-2 - 1)/(4 - 8) = -3/-4 = 3/4

The slope of a perpendicular line is the opposite reciprocal of the slope of the line it's perpendicular to, so we get a slope of -4/3.

We can use point-slope form and get (using point C):

y - (-2) = (-4/3)(x - 4) -->

y + 2 = -4x/3 + 16/3 -->

y = -4x/3 + 10/3

**NOTE** I can't see the picture (because of a problem on my computer) so if there is any info given there that isn't given in the text, then my answer will be incorrect.