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jumb

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Hi everybody!

My 4unit trials tomorrow and was wondering, which topic of the trials did you find the hardest, exluding mechanics?

Also, is the integral of (Loge x) and (e^x) the same as their unintegrated selves?
 

ngai

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well, in our ruse trial this yr, conics and volumes :D
is the integral of lnx and e^x the same as their unintegrated selves...
hmm, "unintegrated selves"...thats a term i've never heard of
umm...50-50 chance: no?
 

jumb

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lol my bad phrasing :)

i meant: Does the integral of (loge x) = Loge x
and does the intgral of (e^x) = e^x
?
 

withoutaface

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jumb said:
lol my bad phrasing :)

i meant: Does the integral of (loge x) = Loge x
and does the intgral of (e^x) = e^x
?
integral of e^x=e^x, but for lnx nope
 

ngai

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int of lnx = lnx....
just think about it: differentiate y=lnx...thats yr11 stuff
 

ngai

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lol thank you
how did u know?
u have list of prizewinners?
 

jumb

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btw i just noticed i dont know how to spell 'trial'

anyway back to the trails
 

ngai

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hmm, do u know who came 2nd?
how did u go?
 

Maianbarian

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ngai said:
int of lnx = lnx....
just think about it: differentiate y=lnx...thats yr11 stuff
ok differentiate y = lnx.....
y'=1/x

Hmmm, not quite yr 11 stuff :p

hmm by parts I get int lnx = xlnx - x but when I use the integrator (http://integrals.wolfram.com) I only get that it = xlnx....

What did I do wrong there?

edit: woah, I'm definatly doing something wrong because when I put ln(x) in the intergrator it gives (lnx^2)/2
 
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Euler

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Maianbarian said:
hmm by parts I get int lnx = xlnx + x but when I use the integrator (http://integrals.wolfram.com) I only get that it = xlnx....

What did I do wrong there?

edit: woah, I'm definatly doing something wrong because when I put ln(x) in the intergrator it gives (lnx^2)/2
need to put functions into integrator correctly. Press the button "How to enter your input". logarithms base e are Log[x]
 

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