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

For this question, as we are looking for gf(x) so we first need to plug in our formula for f(x) into the g(x) formula, giving us:
2((x+1)^2 - 1)
We can then expand our squared bracket to get:
2(x^2 + 2x + 1 - 1)
We can see the +1 and -1 term now cancel out leaving us with:
2(x^2 + 2x)
And finally we take the common term from within the bracket to the outside (both terms share an x) to finish with:
2x(x + 2)

DM
Answered by Django M. Maths tutor

2524 Views

See similar Maths GCSE tutors

Related Maths GCSE answers

All answers ▸

The area of a square is 49cm^2. The perimeter of the square is equal to the circumference of a circle. Work out the radius of the circle. Give your answer to 1 decimal place.


Make x the subject of the equation. y = 4( 2 + x )/ (6x -1)


Solve (6/x-2)-(2/x+3)=1


By factorising, solve the quadratic equation x^2-8x+15=0


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