Solve x^3+2*x^2-5*x-6=0

First find a root of the function: f(x)=x^3+2x^2-5x-6 f(2)=(2)^3+2*(2)^2-5*(2)-6 =0. Therefore, (x-2)(x^2+Ax+3)=0 where A is an unkown constant. Compare x^2 coeffecients: A-2=2, A=4. So (x-2)(x^2+4x+3)=0. Then factorise the quadratic to get (x-2)(x+3)(x+1)=0. Therefore x=2 or x=-3 or x=-1

Answered by Maths tutor

2381 Views

See similar Maths A Level tutors

Related Maths A Level answers

All answers ▸

Given that y = cos(3x)cosec(5x), use the product rule to find dy/dx.


Let f(x)=xln(x)-x. Find f'(x). Hence or otherwise, evaluate the integral of ln(x^3) between 1 and e.


Differentiate y = 2e^(2x+1)


Find dy/dx when y = (3x - 1)^10


We're here to help

contact us iconContact ustelephone icon+44 (0) 203 773 6020
Facebook logoInstagram logoLinkedIn logo

© MyTutorWeb Ltd 2013–2025

Terms & Conditions|Privacy Policy
Cookie Preferences