Solving a quadratic inequality by the graph
Answers are for parents and teachers.
1
Solve 2x² − 7x + 3 > 0.
x < 1/2 or x > 3
2
Solve −x² + 6x − 9 < 0.
x ≠ 3
3
Solve x² − 4x + 10 ≤ 0.
no solutions (D = 16 − 40 < 0, branches up)
4
Solve 3x² − 12 ≥ 0.
x ≤ −2 or x ≥ 2
5
Write the steps for solving x² − 8x + 12 < 0 by the graph and give the answer.
Branches up; roots 2 and 6; the part below Ox: 2 < x < 6.