This weeks recap (17/1/11 - 21/1/11)

This week, we learnt:

Completing the square!

As you can see, we subtracted both sides by 3, but wait. 5 does not have factors that add up/subtract to get 3! So. We have to do this equation using the "completing the square" method.

We can do this by subtracting the constant on both sides, giving you -3 in this case on the RHS. We then use the "a^2-b^b" method. Because of the 2ab part in the centre, we have to divide 5 by 2, giving us the "b" which is half of 5. BUT. To make both side equal, we have to ADD the "b" to both sides, which is 5/2 in this case. We then factorise and simplify the fractions, giving you the answer :)

(PRACTICE THIS! It is complicated BUT once you get it right, it would be easy for you :))

We can multiply a fraction by (-1)/(-1) and the fraction is still equal.

We also learnt that parabolas are always linked to quadratic equations.

One example of what we learnt:

x^2-5x=-6

(Note: Always make y=0)

x^2-5x+6=0

(Then we factorise)

(x-3)(x-2)=0

Therefore, x-3=0 OR x-2=0

Answer is x=3 OR x=2

(Note: We have to write both ORs down. Both of them are answers!)

Done by Kenneth Teh