Question

Write the equation of the circle with center (-4, 11) and containing the point (5, -1). Use the ^ key for the exponents. Write your answer as the example: (x+2)^2+(y-5)^2=49

Answer 1

(x+4)^2 + (y-11)^2 = 169

Answer 2

Mmm...don't agree

Assuming point (5,-1) lies ON the circle, radius R:

(x+4)^2 + (y-11)^2 = R^2

Sub in x=5 and y=-1 giving

(5+4)^2 + (-1-11)^2 = R^2, or

9^2 + (-12)^2 = 81 + 144 = 225 = R^2

So R =sqrt 225 = 15

Equation of circle therefore

(x+4)^2 + (y-11)^2 = 225