Week 11 – Inequalities

This week we started our new unit on Inequalities. We focused on graphing and writing true statements based on either a graph or an equation. We learnt how to do this with linear equations and quadratic equations.

For example: A linear equation like y>x+4 can easily be graphed by using the slope and y intercept 

Then to make this a true statement about inequalities we need to determine which side of border line will make the original inequality true. To do this we will choose a point on the grid and test it.

0>0+4 –> 0 is not greater than 4 therefore we would shade the top half of the grid 

And, since the inequality states y>x+4, the border line is broken because it will not include 4, if it did it would be a solid line.

For Quadratic Equations you follow 3 steps to determine the solution.

y> -2x-8

1. Graph the parabola

2.Pick a point on the graph

3. Make it a true statement

So… y>(x-2)(x+4)

x=2 and x=-4

Graph

Then pick a point and make it a true statement

(0,0)

0>-8 This is false, therefore you would colour the inside of the parabola