Solve the Inequality X^2 - 2X - 8 < 0

First we need to solve the Inequality, looking at what two numbers add to give -2 and multiply to give -8 we find these to be -4 and +2. So we can now say that (X-4)(X+2)<0. Then I like to draw a quick diagram sketch to help visualise the problem so draw an x^2 sketch with roots at -2 and +4. Found by setting each bracket equal to 0. Then look at where this curve is less than 0 to give us an answer of -2<X<4. I would then recommend plugging in the numbers -3, 1 and 5 as a quick check.

LC

Related Maths GCSE answers

All answers ▸

Solve the following simultaneous equations: x^2 + y^2 = 5, y - 3x = 1.


An triangular prism has base xcm, height (x+4)cm and length 4xcm. Find the volume of the prism in terms of x. Find the volume when x=2cm.


How to find surface area and volume of a cone


how do you solve these simultaneous equations?