How do you implicitly differentiate #xy- yln(x-y)= 4-x#?

1 Answer
Apr 22, 2018

#(dy)/dx=(-y-1+y/(x-y))/(x-ln(x-y)+y/(x-y))#

Explanation:

#d/dx(xy-yln(x-y))=d/dx(4-x)#

#y+x(dy)/dx-(dy)/dxln(x-y)-y/(x-y)*d/dx(x-y)=-1#

#y+x(dy)/dx-(dy)/dxln(x-y)-y/(x-y)(1-(dy)/dx)=-1#

#y+x(dy)/dx-(dy)/dxln(x-y)-y/(x-y)+y/(x-y)(dy)/dx=-1#

now isolate #(dy)/dx#

#x(dy)/dx-(dy)/dxln(x-y)+y/(x-y)(dy)/dx=-y-1+y/(x-y)#

#(dy)/dx(x-ln(x-y)+y/(x-y))=-y-1+y/(x-y)#

#(dy)/dx=(-y-1+y/(x-y))/(x-ln(x-y)+y/(x-y))#