Graphing x^2 + y^2 = 81

Bladesofhalo

New member
How would you graph x[sup:35wqnwfu]2[/sup:35wqnwfu] + y[sup:35wqnwfu]2[/sup:35wqnwfu] = 81. Do I have to solve for y like usual?

stapel

Super Moderator
Staff member
I would suspect that you're supposed to recognise the form of a circle equation, and note that this is a circle centered at the origin, with a radius of nine units. :wink:

Eliz.

Loren

Senior Member
Solving for y will work. If you do so, you will be able to plot several points which will produce the desired circle. Just remember that when you solve for y you will get a $$\displaystyle \pm\sqrt{something}$$