The quadratic function and y = x²
Answers are for parents and teachers.
1
Find the value of y = −x² + 4x − 1 at x = 2.
3
2
Find the zeros of y = x² − 8x + 15.
x₁ = 3, x₂ = 5
3
For which x does y = x² − 4x equal −3?
x = 1, x = 3
4
Find the intersection points of the parabola y = x² and the line y = 3x − 2.
(1, 1), (2, 4)
5
Using the graph, find the x for which y = x² does not exceed 4. Why?
−2 ≤ x ≤ 2; because y(±2) = 4 and the parabola rises as we move away from the vertex.