Question

What is the center of the circle and radius defined by the following equation?

x2+y2+4y=5

Answer 1

Explanation:

Alternate forms:

x^2 + y (y + 4) = 5

x^2 + y^2 + 4 y - 5 = 0

Solutions:

y = -sqrt(9 - x^2) - 2

y = sqrt(9 - x^2) - 2

Integer solutions:

x = ± 3, y = -2

x = 0, y = -5

x = 0, y = 1

Implicit derivatives:

(dx(y))/(dy) = -(2 + y)/x

(dy(x))/(dx) = -x/(2 + y)