Respuesta :
Answer:
[tex] g ( x ) * f ( x ) = ( x + 9 ) ^ 2 [/tex]
Step-by-step explanation:
We are given the following two functions and we are to find [tex]g(x) * f(x)[/tex]:
[tex]f(x)=x2-81[/tex]
[tex]g(x)=(x - 9)^{-1} ( x + 9)[/tex]
[tex]g(x)*f(x)=x^{-81} * \frac{x+9}{x-9}[/tex]
[tex]g ( x ) * f ( x ) =\frac{(x+9)(x-9)(x+9)}{x-9}[/tex]
[tex] g ( x ) * f ( x ) = ( x + 9 ) ( x + 9 ) [/tex]
[tex] g ( x ) * f ( x ) =( x + 9 ) ^ 2 [/tex]
For this case we have the following fusions:
[tex]f (x) = x ^ 2-81\\g (x) = (x-9) ^ {- 1} * (x + 9)[/tex]
We can rewrite g (x) as:
- [tex]g (x) = \frac {(x + 9)} {(x-9)}[/tex]
According to the following power property:
[tex]a ^ {- 1} = \frac {1} {a ^ 1} = \frac {1} {a}[/tex]
Also:
If we factor f (x) we have:
[tex]f (x) = (x + 9) (x-9)[/tex]
We must find:
[tex]f (x) * g (x) = (x + 9) (x-9) * \frac {(x + 9)} {(x-9)}[/tex]
We simplify common terms in numerator and denominator:
[tex]f (x) * g (x) = (x + 9) ^ 2[/tex]
ANswer:
[tex]f (x) * g (x) = (x + 9) ^ 2[/tex]