Problem

Find the center, radius, and intercepts of the circle with the given equation and then sketch the graph.
\[
x^{2}+y^{2}+4 x-6 y+4=0
\]

Answer

Expert–verified
Hide Steps
Answer

Finally, we sketch the graph with the center at \((-2, 3)\), radius of 3, and the intercepts we found.

Steps

Step 1 :Completing the square gives us \((x + 2)^2 + (y - 3)^2 - 9 = 0\).

Step 2 :Rearranging terms, we have \((x + 2)^2 + (y - 3)^2 = 9\).

Step 3 :It follows that the square of the radius is 9, so the radius must be \(\boxed{3}\).

Step 4 :The center of the circle is at \((-2, 3)\).

Step 5 :To find the intercepts, we set \(x = 0\) in the equation of the circle and solve for \(y\), and vice versa.

Step 6 :For the x-intercepts, we get \(y = 3 \pm \sqrt{9 - 4} = 3 \pm \sqrt{5}\).

Step 7 :For the y-intercepts, we get \(x = -2 \pm \sqrt{9 - 9} = -2\).

Step 8 :So the x-intercepts are \((-2, 3 + \sqrt{5})\) and \((-2, 3 - \sqrt{5})\), and the y-intercept is \((0, -2)\).

Step 9 :Finally, we sketch the graph with the center at \((-2, 3)\), radius of 3, and the intercepts we found.

link_gpt