What are the x-intercepts of the graph of the function [tex]\( f(x) = x^2 + 4x - 12 \)[/tex]?

A. [tex]\((-6,0),(2,0)\)[/tex]

B. [tex]\((-2,-16),(0,-12)\)[/tex]

C. [tex]\((-6,0),(-2,-16),(2,0)\)[/tex]

D. [tex]\((0,-12),(-6,0),(2,0)\)[/tex]



Answer :

To find the [tex]\( x \)[/tex]-intercepts of the function [tex]\( f(x) = x^2 + 4x - 12 \)[/tex], we need to determine the values of [tex]\( x \)[/tex] for which [tex]\( f(x) = 0 \)[/tex]. The [tex]\( x \)[/tex]-intercepts occur where the graph of the function crosses the [tex]\( x \)[/tex]-axis.

Let's set the function equal to zero:
[tex]\[ x^2 + 4x - 12 = 0 \][/tex]

This is a quadratic equation in the form [tex]\( ax^2 + bx + c = 0 \)[/tex]. Here, [tex]\( a = 1 \)[/tex], [tex]\( b = 4 \)[/tex], and [tex]\( c = -12 \)[/tex].

To find the [tex]\( x \)[/tex]-values that satisfy this equation, we use the quadratic formula:

[tex]\[ x = \frac{{-b \pm \sqrt{{b^2 - 4ac}}}}{2a} \][/tex]

First, we calculate the discriminant ([tex]\( \Delta \)[/tex]):

[tex]\[ \Delta = b^2 - 4ac \][/tex]

Plugging in the values of [tex]\( a \)[/tex], [tex]\( b \)[/tex], and [tex]\( c \)[/tex]:

[tex]\[ \Delta = 4^2 - 4 \cdot 1 \cdot (-12) \][/tex]
[tex]\[ \Delta = 16 + 48 \][/tex]
[tex]\[ \Delta = 64 \][/tex]

Next, we substitute the discriminant and the coefficients [tex]\( a \)[/tex] and [tex]\( b \)[/tex] back into the quadratic formula:

[tex]\[ x = \frac{{-4 \pm \sqrt{64}}}{2 \cdot 1} \][/tex]
[tex]\[ x = \frac{{-4 \pm 8}}{2} \][/tex]

This gives us two solutions:

[tex]\[ x_1 = \frac{{-4 + 8}}{2} = \frac{4}{2} = 2 \][/tex]

[tex]\[ x_2 = \frac{{-4 - 8}}{2} = \frac{-12}{2} = -6 \][/tex]

Thus, the [tex]\( x \)[/tex]-intercepts of the function [tex]\( f(x) = x^2 + 4x - 12 \)[/tex] are:

[tex]\[ (2, 0) \quad \text{and} \quad (-6, 0) \][/tex]

Therefore, the correct answer from the provided options is:

[tex]\[ \boxed{(-6,0),(2,0)} \][/tex]