Quadratic Functions : Circles, Parabola, Elipse, Hyperbola

 Standard form of a Quadratic: ax² + bx + cy² + dy+e=0

If you have an equation like 7x² + 7y²=49 The equation is a circle, because a=c
http://www.webmath.com/cgi-bin/grapher.cgi?answer=y&cgiCall=grapher&getPost=get&param0=3&param1=-&param2=&param3=&param4=-&param5=&param6=&param7=-&param8=&param9=-&param10=&param11=&ymax=10&xmin=-10&xmax=10&ymin=-10&to_plot=circle

If a or c equals 0, the equation is a parabola ( ex: 7x² + 6y= 9)

If a or c have different signs the equation is a hyperbola ( for example: 2x² - 2y²= 8)

If you have an equation like 3x² + 4y²= 24 the equations is an ellipse, because a is not equal to c and the signs are the same


(x-h)² +(y-k)² =r ²  Standard form of a circle

Circle Formula      
 C=πr²                                                     Radius= diameter/2
 A=πr²                                                    Diameter=2r
What is a trinomial perfect square?
(a+b)²