My center (8,-1) & my radius is 4. How do I solve for x & y intercepts and graph it?
The equation of a circle with center (h,k) and radius r is
(x - h)² + (y - k)² = r²
(h,k) = (-8,-1) and r = 4, so the equation is
(x - 8)² + (y - (-1))² = 4²
(x - 8)² + (y + 1)² = 16
The graph is
The x-intercepts are when y=0, so we substitute y=0 in
(x - 8)² + (0 + 1)² = 16
(x - 8)² + 1 = 16
(x - 8)² = 15
Use the principles of square roots:
x - 8 = ±
x = 8 ±
The x-intercepts are
(
, 0) and (
, 0)
which are approximately (4.13,0) and (11.87,0)
Edwin