Question 72188
<pre>
x^2 – x – 20   find the positive discriminant
X^2 – 16x + 64  find zero discriminant
3x2 + 4x + 2   find negative discriminant


1) Value for :   a=1, b= -1, c = 
2)Calculation
3)Value of discriminant 
4)What the value of the discriminant means to the graph

explain what this means to the graph : y=ax^2 + bx + c


A. x^2 – x – 20   find the positive discriminant
 1. Values for : a = 1, b = -1 and c = -20
 2. To find the discriminant x = b^2 - 4ac
                               = (-1)^2 - 4(1)(-20)
                               = 1 + 80
 3.                            = 80        -------------> positive discriminant
 4. Discriminant determines the solution of the equation and x intercept.
    since we have positive discriminant, we have 2 solutions and 2 x-intercept.



B. x^2 – 16x + 64  find zero discriminant
 1. Values for : a = 1, b = -16, c = 64
 2. Solve for the discriminant x = b^2 - 4ac
                                 = (-16)^2 - 4(1)(64)
                                 = 256 - 256
 3.                              = 0 -------------> Zero Discriminant
 4. Since we have Zero discriminant, we have 1 soution and 1 x-intercept



C. 3x^2 + 4x + 2   find negative discriminant
 1. Value for: a = 3, b = 4, c = 2
 2. x = b^2 - 4ac
      = 4^2 - 4(3)(2)
      = 16 - 24
 3.   = -8 --------------> negative discriminant
 4. Since it is a negative discriminant, there is no solution or no x-intercept

Example Let us solve for x: x^2 – x – 20
                            (x -5)(x + 4)
                            x = 5  and x = -4 2 solutions


                           x^2 – 16x + 64
                           (x -8)(x - 8)
                            x = 8   one solution

You can solve for x for 3x^2 + 4x + 2 using quadratic formula and you will get no solution.

I hope this help