2 — $x = \frac{-(-4)}{2 \times 1} = \frac{4}{2} = 2$.

Question 1

For $f(x) = 2x^2 + 3x - 5$, does the parabola open upward or downward?

Accepted Answer

Upward — Since $a = 2 > 0$, the parabola opens upward.

Question 2

For $f(x) = x^2 - 6x + 8$, find the y-intercept by evaluating $f(0)$.

Accepted Answer

8 — $f(0) = 0 - 0 + 8 = 8$, so the y-intercept is $8$.

Question 3

For $f(x) = x^2 - 4x + 3$, find the x-coordinate of the turning point using $x = -\frac{b}{2a}$.

Accepted Answer

2 — $x = \frac{-(-4)}{2 	imes 1} = \frac{4}{2} = 2$.

Functions

Sample practice questions