3. The Discriminant
The discriminant is the part of the
quadratic formula inside the radicand.
The discriminant tells you the
number of solutions and should be
computed first. If the discriminant is:
= 0; 1 solution
> 0; 2 solutions
< 0 no solutions
y = 4x2 – 17x – 15
How many times does the graph cross the x axis?
5. We will start with a simple case of a radical in the
denominator. This must be removed. Why?
Rationalizing the Denominator
By "rationalizing the denominator." (Changing the denominator
from a radical number to a rational one.)
It’s just a generally agreed upon thing in math, that’s all.
Simplify: Finally:
How is it done?
That's right! Of course, we must do the same to both & bottom
10 2
This is done by removing the square root from the denominator.
How can we make the denominator 2?
8. You can solve equations using the method of your choice on the test.
However, the easiest, (or only ) method will often be the quadratic
formula.
Quadratic Exam Review
Look carefully at the equation, then determine the best
(easiest) method of solving. Or....
Possible solution methods?
Possible solution methods?4x2 = 24 - 4x–5 ± 21
2 ± 13
....Solve by factoring
9. Quadratic Exam Review
Write the quadratic equation when given the solution
Start with 'a' and 'b'.
And then 'c'.
The equation is: 8x2 + 3x - 9 =0
