AS/A2 Pure 2 Pure 3

P1 Topic 2: Algebra
Quadratic inequalities
The graph of y = x2-3x is shown. The region above the x axis is coloured purple and the region below is green. The region where x2-3x < 0 is that part of the graph under the x-axis, where the curve is green, in other words the part where 0 < x < 3. Therefore the solution to the inequality x2-3x < 0 is 0 < x < 3. Change the values of a, b and c, and solve ax2+bx+c < 0

Summary When solving any inequality ax2+bx+c < 0, you will first need to solve the equation ax2+bx+c = 0 Note the difference that positive or negative a makes to the solution Based on free Java applets from JavaMath