the graph of the function f(x)=(x + 2)(x + 6) is shown below. what is true about the domain and range of the…

the graph of the function f(x)=(x + 2)(x + 6) is shown below. what is true about the domain and range of the function? the domain is all real numbers, and the range is all real numbers greater than or equal to -4. the domain is all real numbers greater than or equal to -4, and the range is all real numbers. the domain is all real numbers such that -6≤x≤-2, and the range is all real numbers greater than or equal to -4. the domain is all real numbers greater than or equal to -4, and the range is all real numbers such that -6≤x≤-2.

the graph of the function f(x)=(x + 2)(x + 6) is shown below. what is true about the domain and range of the function? the domain is all real numbers, and the range is all real numbers greater than or equal to -4. the domain is all real numbers greater than or equal to -4, and the range is all real numbers. the domain is all real numbers such that -6≤x≤-2, and the range is all real numbers greater than or equal to -4. the domain is all real numbers greater than or equal to -4, and the range is all real numbers such that -6≤x≤-2.

Answer

Explanation:

Step1: Recall domain definition

For a polynomial function like $f(x)=(x + 2)(x+6)=x^{2}+8x + 12$, the domain is all real - numbers since there are no restrictions on the value of $x$ for which the function is undefined.

Step2: Find the vertex of the parabola

The function $y=x^{2}+8x + 12$ is a quadratic function in the form $y=ax^{2}+bx + c$ with $a = 1$, $b = 8$, $c = 12$. The $x$ - coordinate of the vertex is $x=-\frac{b}{2a}=-\frac{8}{2\times1}=-4$. Substitute $x=-4$ into the function: $y=(-4)^{2}+8\times(-4)+12=16-32 + 12=-4$. Since $a = 1>0$, the parabola opens upward, and the minimum value of the function is $y=-4$. So the range is all real numbers greater than or equal to $-4$.

Answer:

The domain is all real numbers, and the range is all real numbers greater than or equal to -4.