Question

The general form of the equation of a circle is 7x2 + 7y2 − 28x + 42y − 35 = 0. The equation of this circle in standard form is ____. The center of the circle is at the point____ , and its radius is_____ units.

Answer 1

A. (x - 2)^2 + (y + 3)^2 = 18.

B. (2, -3)

C. 3(2^(1/2))

Explanation:

The equation of this circle in standard form is (x - 2)^2 + (y + 3)^2 = 18. The center of the circle is at the point (2, -3), and its radius is 3(2^(1/2)) units.

Answer 2

= 7(x^2 + y^2 - 4x + 6y - 5)= 0

= 7( (x - 2)^2 - 4 + (y + 3)^2 - 9 - 5) = 0

= 7[ (x - 2)^2 + (y + 3)^2 - 18) = 0

center is at (2,-3) and radius = sqrt18 = 4.24 units