Math Is Fun Forum

taylor_2009

Member

Registered: 2010-01-25

Posts: 28

Find the coordinates of the maximum point?

y= (13x)/(1+.25x)² for x≥0

Find the coordinates of the maximum point.

I got y'=[13+6.5x-12.9x²]/(1+.25)² but when I set that equal to 0 and then used the quadratic equation to solve, I got a negative number under the radical, so I know that I did something wrong. I can't figure this one out.

bobbym

bumpkin

From: Bumpkinland

Registered: 2009-04-12

Posts: 109,606

Re: Find the coordinates of the maximum point?

Hi taylor_2009;

x = 4

Maximum occurs at (4,13)

Graph f(x) to check:

http://www.mathsisfun.com/graph/functio … 4.12591175

Indeed their is a maximum at x = 4.

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In mathematics, you don't understand things. You just get used to them.
If it ain't broke, fix it until it is.
Always satisfy the Prime Directive of getting the right answer above all else.

soroban

Member

Registered: 2007-03-09

Posts: 452

Re: Find the coordinates of the maximum point?

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