f(x) = (x+1)^2 and g(x) = 2(x-1); Show that gf(x) =2x(x+2)

In this question, we are being asked to combine the functions f(x) and g(x). The function gf(x) is 'putting in' the function f(x) into g(x). What we do is substitute whatever f(x) is into the g function like so:gf(x) = g(f(x)) = g ((x+1)^2) = 2 ((x+1)^2 - 1) = 2((x^2 + 2x + 1) - 1) = 2 (x^2 +2x)We can then factor out the x to get 2x(x+2), which is what we were asked to prove.

MS
Answered by Meera S. Maths tutor

6851 Views

See similar Maths GCSE tutors

Related Maths GCSE answers

All answers ▸

Five Chocolate bars cost £11. Three Chocolate Bars and two packs of Biscuits cost £13.6. How much does two Chocolate bars and one pack of biscuits cost.


Find the Lowest common multiple of 96 and 132


Derive the quadratic formula form the general quadratic equation


Factorise 5 – 10m


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