Solve x^4+2x^2-3=0

The trick with this question is noticing the hidden quadratic as quartic equations are unsolvable at A-level.

Letting u=x^2 the question becomes u^2+2u-3=0 which most students would be able to solve.

To factorise this then we must find two numbers that add to 2 and multiply to give -3, i.e. 3 and -1. 

Therefore factorising this becomes: (x+3)(x-1)=0 x therefore equals -3 and 1

Answered by Ben S. Maths tutor

6721 Views

See similar Maths A Level tutors

Related Maths A Level answers

All answers ▸

Show using mathematical induction that 8^n - 1 is divisible by 7 for n=1,2,3,...


How do you find the possible values of cos(x) from 5cos^2(x) - cos(x) = sin^2(x)?


Find the roots of the following quadratic equation: x^2 +2x -15 =0


Solve algebraically: 2x - 5y = 11, 3x + 2y = 7


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