What is the inverse of f(x)=2x−3 ?


What is the inverse of the function?

f(x)=4x+10


What is the inverse of f(x)=x4+7 for x≥0 where function g is the inverse of function f?

Verified Answer :

The inverse of f(x)=2x−3 is f(x)=(x+3)/2, the inverse of the function f(x)=4x+10 is f(x)=(x-10)/4. 
The 3rd question is not clear. What is x4 and where is the function g?

Answer and Explanation :

We have to find the inverse of the functions below :

1) \(f(x)=2x-3\)

Let f(x)=y

\(y=2x-3\)

Replace the value of x and y,

\(x=2y-3\)

Now we find y,

\(x+3=2y\)

\(y=\frac{x+3}{2}\)

The inverse of the function is \(f^{-1}(x)=\frac{x+3}{2}\)

2) \(f(x)=4x+10\)

Let f(x)=y

\(y=4x+10\)

Replace the value of x and y,

\(x=4y+10\)

Now we find y,

\(x-10=4y\)

\(y=\frac{x-10}{4}\)

The inverse of the function is \(f^{-1}(x)=\frac{x-10}{4}\)

3) \(f(x)=x^4+7\) for x≥0

Let f(x)=y

\(y=x^4+7\)

Replace the value of x and y,

\(x=y^4+7\)

Now we find y,

\(x-7=y^4\)

\(y=(x-7)^{\frac{1}{4}}\)

The inverse of the function is \(g(x)=(x-7)^{\frac{1}{4}}\)