Question

What is the radius of a circle with the equation x^2 +y^2+ 2x + 4y - 9 = 0?

Answer 1

Answer:

x^2+y^2+2x+4y-9=0

x^2+2x+y^2+4y=9

x^2+2.1.x+1-1+y^2+2.2.y+4-4=9

(x+1)^2+(y+2)^2=9+1+4=14

R^2=14

R=sqrt14=3.742

Step-by-step explanation: