This powerpoint presentation discusses or talks about the topic or lesson Quadratic Inequalities. It also discusses and explains the rules, steps and examples of Quadratic Inequalities.
4. Example: x2 + x – 6 = 0
(x + 3) (x-2) > 0
The inequality states that the product of x + 3
and x – 2 is positive. If both factors are positive
or both negative, the product is positive
5. Value Where On the Number Line
x + 3 = 0 If x = -3 Put a 0 above –3
x + 3 > 0 If x > -3 Put + signs to the right of -3
x + 3 < 0 If x < -3 Put – signs to the left of -3
Value Where On the Number Line
x + 2 = 0 If x = -2 Put a 0 above –2
x + 2 > 0 If x > -2 Put + signs to the right of -2
x + 2 < 0 If x < -2 Put – signs to the left of -2
6. x – 2 - - - - - - - - + + + + +
x + 3 - - - 0 + + + + 0 + + + +
-6 -5 -4 -3 -2 -1 0 1 2 3 4 5 6
We can see from the sign graph that the product is positive if x <-3
and also positive if x > 2.
Positive product
since both factors
are negative
Positive product
since both factors
are positive
7. Steps in solving a Quadratic
Inequality with a sign Graph
1. Write the inequality with 0 on the right
side
2. Factor the quadratic trinomial
3. Prepare a sign graph showing where
each factor is positive, negative, or zero
4. Use the rules for multiplying signed
numbers to determine which regions
satisfy the original inequality
8. 3𝑥 − 4
𝑥 − 2
≥ 2
3𝑥 − 3
𝑥 + 4
≤ 0
These inequalities are called Rational
inequalities