Question

What is the standard form of the equation for this circle?

A. -(x – 1)2 – (y + 10)2 + 4 = 0
B. (x – 1)2 – (y + 10)2 = 2
C. (x + 1)2 + (y – 10)2 = 4
D. (x – 1)2 – (y + 10)2 = 4

A (-1, 10)
Radius 2

Answer 1

C

Explanation:

The equation of a circle in standard form is

(x - h)² + (y - k)² = r²

where (h. k) are the coordinates of the centre and r is the radius

here (h, k) = (- 1, 10) and r = 2, thus

(x - (- 1))² + (y - 10)² = 2², that is

(x + 1)² + (y - 10)² = 4 → C