AS Maths

@hrashid_

When you have an expression in brackets, then that bracket has a power, it works like the following:

So as you can see, the power times everything in the brackets. So similarly if you have:

Focus on the

Simplify that, then times it by x

As for question 5,

imagine if

And they said work out

They basically mean just work out

Which is just

So similarly, try the same thing.

@lilyy

When you complete the square, you have the line of symmetry

say for example you had a quadratic and you completed the square and you got:

(x- 5)^2 +  3

Do you know what the minimum point of this quadratic would be?

@hrashid_

You need to pretend like they're quadratics

I'll do the first one for you

x^6 + 9x^3 + 8

If you want to make that look like a quadratic (clearly its not right now) you need to pretend x^3 = y

This will make the expression above turn into

y^2 + 9y + 8 which looks much more like a quadratic now

(as y^2 = x^6)

Then you just solve y^2 + 9y + 8 = 0

(y + 8)(y + 1) = 0

y = -8, y = -1

But remember earlier we said x^3 = y

So really 

x^3 = -8, x^3 = -1

so x = -2, x = -1

Finished