∑ DANEMATHICS
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Grade 11 · Equations and Inequalities
Quadratic Inequalities (Grade 11)
MEMORANDUM
Name:
Class:
Date:
Mark
/ 18
Answer all questions. Show all your working — marks are awarded for method as well as the final answer. Teacher copy: accept any correct equivalent method.
- 1Solve x² − x − 6 > 0(3)(x − 3)(x + 2) > 0 → x < −2 or x > 3✓✓✓ (3)
- 2Solve x² − x − 6 ≤ 0(3)−2 ≤ x ≤ 3, i.e. [−2 ; 3]✓✓✓ (3)
- 3Solve x² − 9 < 0(2)−3 < x < 3✓✓ (2)
- 4Solve x² − 4 ≥ 0(2)x ≤ −2 or x ≥ 2✓✓ (2)
- 5Solve x² + 5x + 6 < 0(3)(x + 2)(x + 3) < 0 → −3 < x < −2✓✓✓ (3)
- 6Solve x² − 5x > 0(2)x(x − 5) > 0 → x < 0 or x > 5✓✓ (2)
- 7Solve −x² + 4 > 0(2)−2 < x < 2✓✓ (2)
- 8Write x < −1 or x > 4 in interval notation.(1)(−∞ ; −1) ∪ (4 ; ∞)✓ (1)
TOTAL: 18 marks