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

Multiplying Matrices

To determine whether or not matrices can be multiplied you first have to write a dimensions statement.

Example of a dimensions statement:
[ 8 7 ]  [ 4 ]
[ 5  2 ]  [ 1 ]

Dimensions statement:
2 X 2 times 2 X 1



These matrices can be multiplied, so you would multiply row by column.
 Get the sum of the products.
The numbers in yellow tell you that you can multiply the matrices.
The numbers in green tell you the size of the final matrix.