The problem provides a quadratic function $f(x) = px^2 + 5x + q$ and its minimum point $(-2.5, -2.25)$. We are asked to: (a) Find the value of $p$, given that $p$ is an integer and $-2 < p < 2$. (b) Using the value of $p$ from (a), calculate $q$ and state the equation of the axis of symmetry. (c) Determine if the quadratic function changes if the graph is reflected in the x-axis and express the result in the form $f(x) = ax^2 + bx + c$.
2025/4/25
1. Problem Description
The problem provides a quadratic function and its minimum point . We are asked to:
(a) Find the value of , given that is an integer and .
(b) Using the value of from (a), calculate and state the equation of the axis of symmetry.
(c) Determine if the quadratic function changes if the graph is reflected in the x-axis and express the result in the form .
2. Solution Steps
(a) Finding the value of :
Since is an integer and , the possible values for are . A quadratic function must have , and since the parabola opens upwards, . Therefore, .
(b) Finding the value of and the axis of symmetry:
We know that the vertex of the parabola is at . The x-coordinate of the vertex is given by , where and . In this case, .
So, , which is true.
Since the vertex is , we have .
The axis of symmetry is a vertical line passing through the x-coordinate of the vertex, which is .
(c) Reflection in the x-axis:
When the graph of is reflected in the x-axis, the new function becomes .
If , then .
Therefore, if the graph is reflected over the x-axis, the quadratic function becomes .
3. Final Answer
(a)
(b) . The equation of the axis of symmetry is .
(c) Yes, the function changes. The reflected function is .