Quadratic Inequalities

Quadratic Inequalities

“Belong” Game • Students number off 1-4. • Look at the group of 4 things. Evaluate items to decide if your number “belongs”. Write Yes or No because _____________ to justify your choice (independently). • Discuss with small group. • Share with whole class.

Does it belong? Group A 1 2 3 4

Thoughts? • Not blue • Not start with letter “b” • Living vs. Non-living

Does it belong? Group B 1 2 3 4

Thoughts? • Equation • Linear, not Quadratic • Had a Greatest Common Factor

Does it belong? Group C 1 2 3 4

Thoughts? • Trinomial • Underline Inequality “less than or equal” • Standard Form ++ c

Inequalities

Solving Inequalities Notes Step #1: Find Vertex Step #2: Find which way parabola opens Step #3: Find y-intercept (and symmetrical point) Step #4: Sketch the parabola (solid or dashed?) Step #5: Shade above or below the parabola. at “A” at “C”

= -4.5 Opens Up Y-intercept = 8 ~Try It~ Greater=Above + + 8 = 12.25 Symmetrical? + + 8 > 0 Step #1: Find Vertex Step #2: Find Direction Step #3: Find y-intercept Step #4: Sketch Step #5: Shade

= 1 Opens UP Less = Above Symmetrical? ~Try It~ – 8 = -9 Y-intercept = -8 – 8 >0 Step #1: Find Vertex Step #2: Find Direction Step #3: Find y-intercept Step #4: Sketch Step #5: Shade

= -.5 Symmetrical? ~Try It~ + 6 = 5.75 + 6> 0 Step #1: Find Vertex Step #2: Find Direction Step #3: Find y-intercept Step #4: Sketch Step #5: Shade Greater = Above Y-intercept = 6 Opens UP

Quadratic Inequalities