Given:
#f(x)=(x-x^(1/2))/(x^(1/9))#
Let #y=f(x)#
Then,
#y=(x-x^(1/2))/(x^(1/9))#
Simplifying further,
#(x-x^(1/2))/(x^(1/9))=(x)/(x^(1/9))-(x^(1/2))/(x^(1/9))#
#y=(x)/(x^(1/9))-(x^(1/2))/(x^(1/9))#
#(x)/(x^(1/9))=x^(1-1/9)=x^(8/9)#
#(x^(1/2))/(x^(1/9))=x^((1/2-1/9))#
#1/2-1/9=9/18-2/18#
#=(9-2)/18=7/18#
#x^((1/2-1/9))=x^(7/18)#
#(x^(1/2))/(x^(1/9))=x^(7/18)#
#(x)/(x^(1/9))-(x^(1/2))/(x^(1/9))=x^(8/9)-x^(7/18)#
#y=x^(8/9)-x^(7/18)#
#(dy)/(dx)=d/(dx)(y)#
#d/dx(y)=d/dx(x^(8/9)-x^(7/18))#
By the sum rule
#d/dx(x^(8/9)-x^(7/18))=d/dx(x^(8/9))-d/dx(x^(7/18)))#
#d/dx(x^(8/9))=8/9x^((8/9-1))#
#d/dx(x^(8/9))=8/9x^(-1/9)##
#d/dx(x^(7/18))=7/18x^((7/18-1))#
#d/dx(x^(7/18))=7/18x^(-11/18)#
#d/dx(x^(8/9))-d/dx(x^(7/18))=8/9x^(-1/9)-7/18x^(-11/18)#
#d/dx(x^(8/9)-x^(7/18))=8/9x^(-1/9)-7/18x^(-11/18)#
#d/(dx)(y)=8/9x^(-1/9)-7/18x^(-11/18)#
#dy/dx=8/9x^(-1/9)-7/18x^(-11/18)#