Lesson 84: Identifying Quadratic Functions — Practice Questions

1. 1. Which of the following functions is a quadratic function?

   • A. f(x) = 3x - 5
   • B. $g(x) = 4x^3 + 2x^2$
   • C. $h(x) = 1 - 9x^2$
   • D. k(x) = 7

2. 2. The function $f(x) = 8 - 2x + 5x^2$ is a quadratic function. What is the value of the coefficient $a$? ___

3. 3. For the quadratic function $g(x) = 3x^2 - 11$, what is the value of the coefficient $b$? ___

4. 4. When the function $p(x) = 4x + 6x^2 - 1$ is written in standard form, what is the value of the coefficient $c$? ___

5. 5. Which option shows the function $f(x) = 10 + x^2 - 5x$ written in standard form?

   • A. $f(x) = x^2 - 5x + 10$
   • B. $f(x) = 10 - 5x + x^2$
   • C. $f(x) = -5x + x^2 + 10$
   • D. $f(x) = x^2 + 10 - 5x$

6. 6. Which of the following equations represents a quadratic function?

   • A. y = 4x - 9
   • B. $y = 2x^3 - x^2$
   • C. $y = 7 - x + 5x^2$
   • D. y = 12

7. 7. The function $y = 6x + 7 - 4x^2$ is a quadratic function. When written in standard form $y = ax^2 + bx + c$, what is the value of $a$? The value is ___.

8. 8. If the equation $y + 4x = 8x^2 - 1$ is written in the standard form of a quadratic function, $y = ax^2 + bx + c$, what is the value of the constant term $c$? The value is ___.

9. 9. Why is the function $f(x) = 4x^3 - 2x^2 + 5$ not a quadratic function?

   • A. It is missing the linear term.
   • B. The leading coefficient is not 1.
   • C. The highest power of x is 3.
   • D. It includes a constant term.

10. 10. Consider the function $y = 10 - x^2 + 9x$. When written in standard form $y = ax^2 + bx + c$, what is the value of the linear coefficient $b$? The value is ___.