Question

2 Select the correct answer. What is the inverse of function ? F(x)=10/9x+11 A.f-1(x)=9x-99/10 B.f-1(x)=9/10x+11 C.f-1(x)=9x+11/10 D.f-1(x)=10x-110/9

Answer 1

Consider f(x)=y.

`\begin{gathered} f(x)=y \\ x=f^(-1)(y) \end{gathered}`

Simplify the equation f(x)=y to obtain the value of x in terms of y.

`\begin{gathered} f(x)=y \\ (10)/(9)x+11=y \\ (10)/(9)x=y-11 \\ 10x=9y-99 \\ x=(9y-99)/(10) \end{gathered}`

So inverse of function is,

`f^(-1)(x)=(9y-99)/(10)`

Correct nswer is A part.