How do you graph x^2 + y^2 + 2x - 3 = 0?

1 Answer

it is a circle with radius r=2 and center at (h, k)=(-1, 0)

Explanation:

From the given equation x^2+y^2+2x-3=0
perform completing the square method to determine if its a circle, ellipse, hyperbola. There are 2 second degree terms so we are sure it is not parabola

x^2+y^2+2x-3=0
x^2+2x+y^2=3
add 1 to both sides of the equation
x^2+2x+1+y^2=3+1
(x^2+2x+1)+y^2=4
(x+1)^2+(y-0)^2=2^2
it takes the form
(x-h)^2+(y-k)^2=r^2
with center at (-1, 0) with radius r=2

See the graph of x^2+y^2+2x-3=0
graph{(x+1)^2+(y-0)^2=2^2[-10,10,-5,5]}
God bless .... I hope the explanation is useful.