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easy log question, help (1 Viewer)

BoganBoy

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This is probably really easy but i dont know where to start.

Differentiate
y=x^x

Can someone please help? Thanks
 

香港!

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BoganBoy said:
This is probably really easy but i dont know where to start.

Differentiate
y=x^x

Can someone please help? Thanks
y=x^x
ln y=ln x^x=xlnx
(1\y)y'=lnx+1
y'=y(lnx+1)
 

BoganBoy

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can you please explain how you got (1\y)y'? what does it represent? Thanks
 

Dumsum

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Implicit Differentiation rocks my socks.

As an addendum, I'm pretty sure this is beyond 2u scope.
 

klaw

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mojako said:
HK attack!

if u dont want to use the method they do in Hong Kong,
y=x^x
y=e^(x lnx)

if u=x lnx,
du/dx = 1 lnx + x 1/x = lnx + 1

y=e^(x lnx)
y = (lnx + 1) e^(x lnx)

hihihihihi

*flee!*

*comes back*
anyway u wont get this kind of question

*steal!*
*flee!*
isn't substitution calculus also beyond 2U?
 

mojako

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klaw said:
isn't substitution calculus also beyond 2U?
well.. depends on what substitution it is
i think 2u ppl shud be able to differentiate
y=e^(x lnx)
or maybe simpler ones like y=e^sinx

but the trick with this q is to get
y=x^x
y=e^(x lnx)

and that shudnt be in 2u
 

香港!

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if u have
y=e^x
when u differentiate it would be
y'=e^x

in the process u let u=x already
so that's also "substitution" LoL
 

mattchan

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mojako said:
well.. depends on what substitution it is
i think 2u ppl shud be able to differentiate
y=e^(x lnx)
or maybe simpler ones like y=e^sinx

but the trick with this q is to get
y=x^x
y=e^(x lnx)

and that shudnt be in 2u
They teach this in the 2unit Cambridge Book, in the last section of this topic i think.
 

klaw

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mattchan said:
They teach this in the 2unit Cambridge Book, in the last section of this topic i think.
teach x^x=e^(x lnx) or how to differentiate e's?
 

acmilan

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The derivative of ax is a 2 unit topic, thus all 2 unit students should know that ax = exlna.
 

.ben

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i'm doing 3u and how come we haven't done that yet?:(
 

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