Quadratic Inequalities in One Variable

Solve:

2x² + 5x ≥ 12

• [-4, 1.5]

• (−∞, -4) U (1.5, ∞)

• (−∞, -4] U [1.5, ∞)

• no solution

Solve: 5x - 10x² < 0

• (0, ½)

• [0, ½]

• (−∞, 0) U (½, ∞)

• (- ½ , 0)

Solve:

3x - x² > 0

• (−∞, 0) U (3, ∞)

• (−∞, - 3) U (0, ∞)

• (-3, 0)

• (0, 3)

What is the solution set to the inequality x² - 4x - 5 > 0

• x < -1 or x > 5

• x < -5 or x > 1

• -1 < x < 5

• -5 < x < 1

x² - 9x - 112 ≥ 0

• -7 < x < 16
• -7 ≤ x ≤ 16
• x < -7 or x > 16
• x ≤ -7 or x ≥ 16

What are the zeros?

• x= 0 and x= -4
• x= 0 and x= 4
• y= 0
• x= 2

Tags

CCSS.HSF-IF.C.7A

8x + 140 > 4x^{2
hint: put squared term on the LEFT!}

• -5 < x < 7
• -3 ≤ x ≤ 12
• 4 < x < 15
• -2 < x < 10