# Math Help - Partial derivatives

1. ## Partial derivatives

Hi

Having problem with this one

Let f(x,y) = 4e^2y - xe^y
a) Calculate f(4,0)
b) Calculate f(a, ln(b)). Simplify as much as possible (your answer should not contain e)
c) Calculate the first order partial derivatives f'x(x,y) and f'y(x,y). Simplify as much as possible

I dont know what to do when "e" shows up.

Thanks!!

2. Originally Posted by Lippi86
Hi

Having problem with this one

Let f(x,y) = 4e^2y - xe^y
a) Calculate f(4,0)
b) Calculate f(a, ln(b)). Simplify as much as possible (your answer should not contain e)
c) Calculate the first order partial derivatives f'x(x,y) and f'y(x,y). Simplify as much as possible

I dont know what to do when "e" shows up.

Thanks!!
What do you mean "I dont know what to do when "e" shows up."?

Do you mean you don't know how to differentiate an exponential function, or do you mean that you don't know how to simplify something like $e^{2 \ln b} = e^{\ln b^2} = b^2$ .... ?