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Help!! Maths question help needed

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!!!
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)
(edited 7 years ago)
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 (x2)2=0(x-2)^2=0 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.
(edited 7 years ago)
Original post by KloppOClock
complete the square

Spoiler

Original post by RDKGames

Spoiler



oh yeah, i just uncompleted it and then recompleted it lol
Reply 5
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
Original post by Zacken
lol


shh i edited it, no one saw that
Original post by KloppOClock
shh i edited it, no one saw that


It's still in the quote :wink:

Spoiler

Original post by RDKGames
It's still in the quote :wink:

Spoiler



lmao i need coffee

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