How do you differentiate y=e^(-x/4)?

1 Answer
Mar 4, 2018

dy/dx=-e^(-x/4)/4

Explanation:

In order to differentiate a function of a function, we use the chain rule. In other words, if y=f(u) and u=f(x), then

dy/dx=dy/(du)(du)/dx

In this case, let u=-x/4 and y=e^u. Then

dy/(du)=e^u=e^(-x/4);

(du)/dx=-1/4

and, importantly,

dy/dx=dy/(du)(du)/dx=e^(-x/4)(-1/4)=-e^(-x/4)/4