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Drawings wont work in the question :)
eish k let me write it then
ok
Determine integral (with top part of it with e^3 and the bottom part of it e^2) of: In(In w)/wlog3w (this 3 its small and just slight below log) is
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\[\int\limits_{e^2}^{e^3}In(Inw)/wlog3w dw\]
i tried to type it
but the 3 in log is slight below the log, its not 3w, the 3 its slightly belowthe log
oh ok so log base 3
yes
ok first get rid of that log by using change of base \[\rightarrow \log_{3}w = \frac{\ln w}{\ln 3} \] simplify the integral \[\rightarrow \ln 3\int\limits_{?}^{?}\frac{\ln (\ln w)}{w \ln w}dw\]
then make substitution u = ln w du = 1/w dw --> dw = w du \[\rightarrow \ln 3\int\limits_{?}^{?} \frac{\ln u}{u}du\]
then use integration by parts: x = ln u dv = 1/u dx = 1/u v = ln u \[\int\limits_{?}^{?} \frac{\ln u}{u}du = \ln^{2}u - \int\limits_{?}^{?} \frac{\ln u}{u}du\] \[2\int\limits_{?}^{?} \frac{\ln u}{u}du = \ln^{2} u\] \[\int\limits_{?}^{?} \frac{\ln u}{u}du = \frac{\ln^{2} u}{2}\] sub back in for u and put limits in \[\rightarrow \ln 3(\frac{\ln^{2} (\ln w)}{2}) from e^{3} \to e^{2}\]
i get about 0.4
thank you i see, i never knew about intergration by parts
do you mind explaining to me how it works
welcome, sure anytime you have a product of 2 functions, you can use integration by parts \[\int\limits_{}^{}f(x)g(x) dx\] assign either f or g as u and the other as dv, where u and v are functions of x this leads to the equation: \[\int\limits_{}^{}u dv = uv -\int\limits_{}^{}v du\] so to use the equation you must find du and v lets say u = f(x) then du = f'(x) then dv = g(x) and v = integral g(x)
here is an example: \[\int\limits_{}^{}xe^{x}dx\] u = x dv = e^x du = dx v = e^x \[\int\limits\limits_{}^{}xe^{x}dx = xe^{x}-\int\limits_{}^{}e^{x} dx\]
k even if both function are are in the division format? e.g. \[e^xdivx\]
u can still use the the formula?
yes, but one of the functions would be 1/x u = e^x dv = 1/x du = e^x v = ln x notice this will not help much though actually integral e^x/x can't be done using regular methods but in general yes even division can be represented as product of 2 functions
oh k see i get it, thank you, Be blessed
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