Help! Finding x and y-intercepts using circle equations

[kalena1964]

If the center is (1,2) and the radius is 9, what are the x and y-intercepts?

I used the (x - h)^2 + (y - k)^2 = r^2 plugging in y = 0 for the x-intercept and x = 0 for the y-intercept.

Then, I got x^2 - 2x - 76 for the x-intercept and y^2 - 4y - 76 for the y-intercept. Am I on the right path? How do I solve it?

 

[galactus]

Just set = to 0 solve each quadratic.

\(\displaystyle x^{2}-2x-76=0\)

You can use the quad formula. It is always an old standby.

If not, compete the square.

\(\displaystyle x=(x-1)^{2}-77=0\)

\(\displaystyle x=1-\sqrt{77}, \;\ x=1+\sqrt{77}\)

Do the same for y.