y=-(x-2)^2 + 4 . If I make x the subject, how will my function look like?

Question

anonymous · Answer

you should expand out the (x-2) first. 
so what you have is:
y = -[(x-2)(x-2)] + 4

what do you get?

marigirl · Answer

is it wrong to go:
$$y=-(x-2)^{2} +4$$ 

move the 4 on to the other side, $$y-4 = -(x-2)^{2}$$

marigirl · Answer

Hi Nuk64, I expanded (x-2) and collected like terms and got to $$-x ^{2}+4x=y$$ .. im a bit confused how to go from there to make x the subject

anonymous · Answer

No, you could do that. It's not wrong. 

Then what you'd do is remove the negative sign. 
so you have:

-(y-4) = (x-2)^2

then get rid of the square by taking the square root of each size.

anonymous · Answer

actually, your way's easier.... don't bother expanding.

anonymous · Answer

yep! and then all you have to do is add 2, and you get your function! :)

marigirl · Answer

oh yea cool, then i got $$x= \sqrt{-y+4} +2$$

marigirl · Answer

thank you! :D

anonymous · Answer

no worries. :)