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March 05, 2026, 12:56:37 pm

Author Topic: stationary points??  (Read 577 times)  Share 

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scatteam_2

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stationary points??
« on: October 20, 2010, 05:35:31 pm »
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Find the coordinates of the stationary point on the curve with equation y = x^2loge(1/x) and determine the
nature of the stationary point

the derivative is -2xlogex - x

THIS IS A NON CALCULATOR QUESTION

i found x = e^-1/2

but how do u do the gradient test
ur meant to pick one value above and below e^-1/2
but this value seems very hard to work with

brightsky

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Re: stationary points??
« Reply #1 on: October 20, 2010, 05:59:21 pm »
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Derivative is . Stationary points given by:





or

Solution:

To test, substitute x = 1/2, dy/dx = -1 ln(1/2) - 1/2 > 0 . Substitute x = 1, dy/dx = -1 [/tex]

So it's a maximum.

EDIT: Sorry, silly mistake. xD
« Last Edit: October 20, 2010, 06:04:45 pm by brightsky »
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