Question #5c268

1 Answer
Nov 16, 2014

Logarithmic Differentiation

#f(x)=(x-1)^x#

by taking the natural log, and #ln x^r=r ln x#,

#=> ln[f(x)]=ln(x-1)^x=x ln(x-1)#

by implicitly differentiating with respect to #x#,

#=> {f'(x)}/{f(x)}=1 cdot ln(x-1)+x cdot 1/{x-1}=ln(x-1)+x/{x-1}#

by multiplying by #f(x)=(x-1)^x#,

#=>f'(x)=[ln(x-1)+x/{x-1}] (x-1)^x#


I hope that this was helpful.