I have a test tomorrow and I don't understand this, please help!
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Recall ,if f(x)=ln[g(x)], then f'(x)=g'(x)/g(x).
The clearest way to me to do this is write this as
ln[f(x)]=ln(x)*ln(x)=[ln(x)]^2.(that is begin by taking
log of both sides). Then, by the above comment,
f'(x)/f(x)=2ln(x)/x (using the chain rule).
Hence
f'(x)=f(x)*2*ln(x)/x=2*ln(x)*x^[ln(x)]…
Hope that helps.
The clearest way to me to do this is write this as
ln[f(x)]=ln(x)*ln(x)=[ln(x)]^2.(that is begin by taking
log of both sides). Then, by the above comment,
f'(x)/f(x)=2ln(x)/x (using the chain rule).
Hence
f'(x)=f(x)*2*ln(x)/x=2*ln(x)*x^[ln(x)]…
Hope that helps.
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x^[ln(x)]=e^(lnx)^2
u=lnx
du=1/x
e^u^2=2ueu^2
2lnxe^(lnx)^2/x
u=lnx
du=1/x
e^u^2=2ueu^2
2lnxe^(lnx)^2/x