Which point is an x-intercept of the quadratic function f(x) = (x - 4)(x + 2)?
(-4, 0), (-2, 0), (0, 2), (4, -2)
Solution:
The x-intercept for any curve is the value of x coordinate of the point where the graph cuts x-axis, or we can say that x-intercept is the value of the x coordinate of a point where the value of y coordinate equal to zero.
Given, f(x) = (x - 4)(x + 2)
Now, change the function into an equation,
f(x) = y
y = (x - 4)(x + 2)
When y = 0,
0 = (x - 4)(x + 2)
⇒ x - 4 = 0
⇒ x = 0 + 4
⇒ x = 4
⇒ x + 2 = 0
⇒ x = 0 - 2
⇒ x = -2
So, the value of x is 4 and -2.
Therefore, (-2, 0) is the x-intercept.
Which point is an x-intercept of the quadratic function f(x) = (x - 4)(x + 2)?
Summary:
The point (-2, 0) is an x-intercept of the quadratic function f(x) = (x - 4)(x + 2).
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