What is the implicit derivative of #1= xe^(4y#?

1 Answer
Dec 2, 2015

#-1/(4x)#

Explanation:

To find an Implicit Derivative, differentiate like normal except remember that when you differentiate a #y# there will be an extra #dy/dx# term, thanks to the Chain Rule.

#d/dx[1=xe^(4y)#]

Product Rule:

#0=e^(4y)d/dx[x]+xd/dx[e^(4y)]#

Find each derivative separately:

#d/dx[x]=1#

#d/dx[e^(4y)]=e^(4y)d/dx[4y]#

#d/dx[4y]=4dy/dx#

So, #d/dx[e^(4y)]=4e^(4y)dy/dx#

Plug them back in:

#0=e^(4y)+4xe^(4y)dy/dx#

#-e^(4y)=4xe^(4y)dy/dx#

#dy/dx=(-e^(4y))/(4xe^(4y))=-1/(4x)#