UNIT+3+Chapter+5+Inequalities


 * Inequalities**

Tuesday 18th Sep and Wednesday 19th Sep

We need to be able to...

(i) Illustrate an inequality (in one variable) on a number line. Remember that a 'filled in dot' represents 'or equal to' and an 'empty dot' means 'strictly greater/less than'

(ii) Solve an inequality in one variable (including a 'sandwich inequality') - we go about this in EXACTLY the same way as we would an equations, with ONE exception. We try to avoid multiplying/dividing by a negative but if we have to (especially with 'sandwich inequalities') we need to 'change the sign(s) round'

(iii) list all INTEGER solutions to a 'sandwich inequality' - this means all the WHOLE numbers that satisfy the inequality.

(iv) illustrate regions on a set of axes that represent inequalities in 2 variables. Again, treat them as equations, use dotted lines for 'strict' inequalities and solid lines for 'or equal to' inequalities, and when you've drawn all the relevant lines work out which region to shade. You'll come across questions that give you a region and ask you to write down the inequalities that define it.

HOMEWORK set on Weds 19th - equations and inequalities sheet due in on Monday 1st October.

Mr Gill was away - the aim of the two lessons was to practise the work on equations and inequalities and then learn about 'changing the subject of a formula' - this is when you need to rearrange a formula to get one letter on its own on one side (and that letter NOT appearing on the other). (i) for 'easy' ones, you just need to follow the age-old rule of 'whatever you do to one side you need to do to the other as well' (ii) there are 'harder' ones - when the letter appears in more than one place. These require you to rearrange so that every term involving the letter is on one side and everything else is on the other. Then you need to FACTORISE, then you need to divide.
 * Monday 24th and Tuesday 25th September**

That homework sheet is due in on Monday!

Everyone resitting should be doing papers!