The domain of the function [tex]f(x)[/tex] is [tex][-1,4][/tex] and the range is [tex][6,7][/tex]. Using interval notation, find the domain and range of [tex]g(x) = -f\left(\frac{1}{4}(x+5)\right)[/tex].

Domain: [tex]\square[/tex]
Range: [tex]\square[/tex]



Answer :

Let's begin by addressing the transformation applied to the function [tex]\(f(x)\)[/tex] to obtain [tex]\(g(x)\)[/tex]. The original domain of [tex]\(f(x)\)[/tex] is [tex]\([-1, 4]\)[/tex] and the range is [tex]\([6, 7]\)[/tex].

First, let's determine the domain of the transformed function [tex]\(g(x) = -f\left(\frac{1}{4}(x + 5)\right)\)[/tex].

1. Identify the input [tex]\(u\)[/tex] to the function [tex]\(f\)[/tex]:
[tex]\[ u = \frac{1}{4}(x + 5) \][/tex]

2. Since [tex]\(f(u)\)[/tex] has a domain of [tex]\([-1, 4]\)[/tex], the transformed variable [tex]\(\frac{1}{4}(x + 5)\)[/tex] must also be within this interval:
[tex]\[ -1 \leq \frac{1}{4}(x + 5) \leq 4 \][/tex]

3. Solve for [tex]\(x\)[/tex] in the inequalities separately:

For the lower bound:
[tex]\[ -1 \leq \frac{1}{4}(x + 5) \][/tex]
Multiply both sides by 4:
[tex]\[ -4 \leq x + 5 \][/tex]
Subtract 5 from both sides:
[tex]\[ -9 \leq x \][/tex]

For the upper bound:
[tex]\[ \frac{1}{4}(x + 5) \leq 4 \][/tex]
Multiply both sides by 4:
[tex]\[ x + 5 \leq 16 \][/tex]
Subtract 5 from both sides:
[tex]\[ x \leq 11 \][/tex]

Combining these results, the domain of [tex]\(g(x)\)[/tex] is:
[tex]\[ -9 \leq x \leq 11 \][/tex]
In interval notation, this is:
[tex]\[ \text{Domain: } [-9, 11] \][/tex]

Next, let's determine the range of the function [tex]\(g(x)=-f\left(\frac{1}{4}(x+5)\right)\)[/tex].

1. The range of [tex]\(f(u)\)[/tex] is [tex]\([6, 7]\)[/tex].

2. The function [tex]\(g(x)\)[/tex] negates the values of [tex]\(f(u)\)[/tex]. Therefore, if [tex]\(f(u)\)[/tex] ranges from 6 to 7, the negated values will range from [tex]\(-6\)[/tex] to [tex]\(-7\)[/tex].

3. Since [tex]\(-7\)[/tex] is smaller than [tex]\(-6\)[/tex], we write the range in the correct interval notation as:
[tex]\[ \text{Range: } [-7, -6] \][/tex]

So, the domain and range of the function [tex]\(g(x)=-f\left(\frac{1}{4}(x+5)\right)\)[/tex] are:

[tex]\[ \text{Domain: } [-9, 11], \text{ Range: } [-7, -6] \][/tex]