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: (4, -5). Radius: -5.

Answer 1

A radius cannot be negative, so r = |−5| = 5. The standard form is

(x − 4)^2 + (y + 5)^2 = 25.

Expanded (general) form: x^2 + y^2 − 8x + 10y + 16 = 0.