Get detailed and accurate answers to your questions on IDNLearn.com. Get comprehensive answers to all your questions from our network of experienced experts.

Which of the following is the inverse of the function [tex]f(x) = x^3 - 5[/tex]?

A. [tex]f^{-1}(x) = \sqrt[3]{x - 5}[/tex]
B. [tex]f^{-1}(x) = \sqrt[3]{x} + 5[/tex]
C. [tex]f^{-1}(x) = \sqrt[3]{x} - 5[/tex]
D. [tex]f^{-1}(x) = \sqrt[3]{x + 5}[/tex]


Sagot :

To determine the inverse of the function [tex]\( f(x) = x^3 - 5 \)[/tex], we must find a function [tex]\( f^{-1}(x) \)[/tex] such that when [tex]\( f(f^{-1}(x)) \)[/tex] and [tex]\( f^{-1}(f(x)) \)[/tex] are applied, we get [tex]\( x \)[/tex] back.

Let's start by setting [tex]\( y = f(x) \)[/tex]:
[tex]\[ y = x^3 - 5 \][/tex]

To find the inverse function, we need to solve for [tex]\( x \)[/tex] in terms of [tex]\( y \)[/tex]:
[tex]\[ y = x^3 - 5 \][/tex]

First, add 5 to both sides to isolate the cubic term:
[tex]\[ y + 5 = x^3 \][/tex]

Next, take the cube root of both sides to solve for [tex]\( x \)[/tex]:
[tex]\[ x = \sqrt[3]{y + 5} \][/tex]

Thus, the inverse function is:
[tex]\[ f^{-1}(x) = \sqrt[3]{x + 5} \][/tex]

So, the correct inverse function of [tex]\( f(x) = x^3 - 5 \)[/tex] is:
[tex]\[ f^{-1}(x) = \sqrt[3]{x + 5} \][/tex]

Among the given options, this matches:
[tex]\[ f^{-1}(x) = \sqrt[3]{x + 5} \][/tex]