Sketch the inequality x^2 - x - 12 > y on a set of axes.

First thing to note: this is a sketch question, and we're asked to sketch a quadratic (because there's an x2 term). So we need to factorise (put the brackets in) to work out where it crosses the x-axis. The trick is to find two numbers which multiply to make the last number (-12) and add to make the middle number (-1). After some thinking, this is 3 and -4.So we can write the quadratic as (x+3)(x-4). Along the x-axis, this equals zero. If two brackets multiply to make zero, then one of those brackets must have been zero. So the graph crosses at x=-3 and x=4. Now, we draw the usual quadratic shape, and shade below the curve.

Answered by Tom P. Maths tutor

2351 Views

See similar Maths GCSE tutors

Related Maths GCSE answers

All answers ▸

Harry drives from Exeter to London in 4 hours at an average speed of 70km/h. Ron drives from Exeter to London in 5 hours. (a) Assuming Ron took the same route as Harry, calculate Ron's average speed.


What is a linear equation?


Simplify 3/(x+1) + (3x-9)/2 = 1, to get a quadratic equation in the format ax^2 + bx + c = 0.


This is a sequence: 2,4,7,11,16. Find the Nth term


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