Answer:
Part 1)
A
Part 2)
C
Step-by-step explanation:
1)
We are given:
[tex]f(x)=5x+1\text{ and } g(x)=x^2-9[/tex]
And that:
[tex]h(x)=f(x)/g(x)[/tex]
And we want to now for which values of x is h(x) undefined.
So, by substitution:
[tex]\displaystyle h(x)=\frac{5x+1}{x^2-9}[/tex]
Remember that for rational functions, the function will be undefined if and only if the denominator is 0.
This is because we cannot divide by 0.
So, to find the values for which the denominator is 0, set the denominator to 0 and solve for x. Therefore:
[tex]x^2-9=0[/tex]
Add 9 to both sides:
[tex]x^2=9[/tex]
Take the square root of both sides. Since we are taking an even-root, we will need plus/minus. Therefore:
[tex]x=\pm 3[/tex]
So, h(x) is undefined for ±3.
Our answer is A.
2)
We are given:
[tex]f(x)=3^x\text{ and } g(x)=3^{2x}-3^x[/tex]
And we want to find:
[tex]h(x)\text{ if } h(x)=f(x)-g(x)[/tex]
So:
[tex]h(x)=3^x-(3^{2x}-3^x)[/tex]
Distribute:
[tex]h(x)=3^x-3^{2x}+3^x[/tex]
Combine like terms:
[tex]h(x)=2(3^x)-3^{2x}[/tex]
Rewrite:
[tex]h(x)=2(3^x)-(3^x)(3^x)[/tex]
Factor out:
[tex]h(x)=3^x(2-3^x)[/tex]
So, our answer is C.
