Question

Determine the equation of the circle graphed below. Circle Standard Form: Center: (h, k). Radius: r. (x-h) ^2+(y-k) ^2=r^2. Center: (-6, 7). Radius: -6.

Answer 1

A radius cannot be negative, so take r = 6. The standard form is

(x - (-6))^2 + (y - 7)^2 = 6^2

or

(x + 6)^2 + (y - 7)^2 = 36.

Expanded (general) form: x^2 + y^2 + 12x - 14y + 49 = 0.