What is the derivative of #xe^(y^x)#?

1 Answer
Apr 11, 2018

#y'=(y/x+y^(x+1)lny)/(xy^x)#

Explanation:

#y=xe^(y^x)#

by taking the natural logarithm to both sides

#lny=lnxe^(y^x)#

using the properties of logarithmic functions :
#lnab=lna+lnb#

so,
#lny=lnx+lne^(y^x)#

#lne^(y^x)=y^xlne#=#y^x#
because #rarr#lne=1#

#lny=lnx+y^x# #rarr##(1)#

let #u=y^x#

by taking the natural logarithm to both sides
#lnu=xlny#

Apply implicit differentiation

#(u')/u=(xy')/y+lny#

substitute for #u#

#u'=y^x(xy')/y+y^xlny#

now back to our original equation (1)

#lny=lnx+u#

Differentiate with respect to #x#
#(y')/y=1/x+u'#

substitute for #u'#

#y'=y/x+y(y^x)(xy')/y+yy^xlny#

simplify

#y'=(y/x+y^(x+1)lny)/(xy^x)#

I hope this was helpful.