118,616 views
21 votes
21 votes
Which conic section does the equation below describe?2x²+2y²-6x+4y+ 1 = 0

User Sanchit Gupta
by
2.4k points

1 Answer

13 votes
13 votes

we have the equation


2x²+2y²-6x+4y+1=0

Group similar terms and move the constant term to the right side


(2x^2-6x)+(2y^2+4y)=-1

Factor the leading coefficient on both terms of the left side


2(x^2-3x)+2(y^2+2y)=-1

Complete the square twice


2(x^2-3x+1.5^2)+2(y^2+2y+1)=-1+4.5+2

Rewrite as a perfect square


2(x-1.5)^2+2(y+1)^2=5.50

Divide both sides by 2


\begin{gathered} (x-1.5)^2+(y+1)^2=(5.50)/(2) \\ \\ (x-1.5)^2+(y+1)^2=2.75 \end{gathered}

we have the equation of a circle

therefore

The answer is a circle

User Andreas Siegel
by
2.9k points
Welcome to QAmmunity.org, where you can ask questions and receive answers from other members of our community.