The function f is defined as f(x) = e^(x-4). Find the inverse of f and state its domain.

Firstly, we let y=f(x) so that y=ex-4. The aim of this question is to find the inverse of y=f(x), and in order to do that, we must rearrange the question so that x becomes the subject of the equation, which will be our inverse function of f. The first step is to eliminate the exponential by applying the loge function to each side of the equation, as loge(ex) = x. Therefore, we get: loge(y)=loge(ex-4), loge(y)=x-4, x=loge(y)+4. Now we have x the subject of the equation, the inverse is loge(y)+4. The question is asking about the inverse of f(x) so we replace y with x and obtain f-1(x) = loge(x) + 4.The domain of f-1(x) is the set of input values that f(x) accepts, so we must find those values. We know that the domain of log(x) only takes values above 0, therefore the domain of f-1(x) is 0 < x < +infinity.

Answered by Rutwik K. Maths tutor

9206 Views

See similar Maths A Level tutors

Related Maths A Level answers

All answers ▸

Find ∫ ( 2x^4 - 4x^(-0.5) + 3 ) dx


Given y=2x(x^2-1)^5, show that dy/dx = g(x)(x^2-1)^4 where g(x) is a function to be determined.


1. The curve C has equation y = 3x^4 – 8x^3 – 3 (a) Find (i) d d y x (ii) d d 2 y x 2 (3) (b) Verify that C has a stationary point when x = 2 (2) (c) Determine the nature of this stationary point, giving a reason for your answer.


Why does the chain rule work?


We're here to help

contact us iconContact usWhatsapp logoMessage us on Whatsapptelephone icon+44 (0) 203 773 6020
Facebook logoInstagram logoLinkedIn logo

© MyTutorWeb Ltd 2013–2025

Terms & Conditions|Privacy Policy
Cookie Preferences