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# Help!! Maths question help needed

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1. Hey I'd really appreciate help with this question please I really can't remember how to do it! Is f(x)=9-(x-2)^2 write down the maximum value of f(x) please leave working out too Thankyou!!!
2. (Original post by Sukjeetsandhu)
Hey I'd really appreciate help with this question please I really can't remember how to do it! Is f(x)=9-(x-2)^2 write down the maximum value of f(x) please leave working out too Thankyou!!!
complete the square

(x-a)^2=b

then max/min is at (a,b)
3. (Original post by Sukjeetsandhu)
Hey I'd really appreciate help with this question please I really can't remember how to do it! Is f(x)=9-(x-2)^2 write down the maximum value of f(x) please leave working out too Thankyou!!!
Why would I leave working out? Have a go at it yourself.

It's a quadratic so it's when so you're not subtracting anything. You can sketch the thing anyway and see it.

Otherwise differentiate it, solve it for x, and plug the solution back through the function.
4. (Original post by KloppOClock)
complete the square
Spoiler:
Show
Pssst.... it's already IN a completed square form
5. (Original post by RDKGames)
Spoiler:
Show
Pssst.... it's already IN a completed square form
oh yeah, i just uncompleted it and then recompleted it lol
6. (Original post by KloppOClock)
complete the square

Set f(x)=0

0=9-(x-2)^2
=9-(x^2-4x+4)
=9-x^2+4x-4
=5-x^2+4x
x^2-4x=5
(x-2)^2-4=5
(x-2)^2=9

So max is at (2,9)
lol
7. (Original post by Zacken)
lol
shh i edited it, no one saw that
8. (Original post by KloppOClock)
shh i edited it, no one saw that
It's still in the quote
Spoiler:
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...and why did you make it equal to 0? No need, you're not finding roots
9. (Original post by RDKGames)
It's still in the quote
Spoiler:
Show
...and why did you make it equal to 0? No need, you're not finding roots
lmao i need coffee

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