2. The Discriminant
The Nature of Roots
b2 4ac
From the quadratic formula is known as the discriminant.
It allows us to determine if the roots are real or imaginary.
If the roots are real it also allows us to determine if there are one or two
roots.
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6. For each of the following quadratics
1. Find the value of the discriminant.
2. Use the value to determine the nature of the
roots.
3. Use to quadratic formula to find the exact
value for the roots of each quadratic.
4. Draw a very rough sketch of what the quadratic might
look like.
a) x2 x 12 = 0
b) x2 + 2x + 18 = 0
c) x2 x + 2 = 0
d) x2 + x 4 = 0
e) x2 6x + 9 = 0
f) x2 + 10x 25 = 0
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