# Another chain rule: easy one (1 Viewer)

### Users Who Are Viewing This Thread (Users: 0, Guests: 1)

#### physicsed

[SOLVED] another chain rule: easy one

$$y=xe^{-x^2}$$

i have no i dea how to start.
$$f'= x^{x^2} or -2x^blah blah blah$$

just get me started and i'll promise you i will finish it myself

Last edited:

#### Feldoh

This is actually an application of the product rule, then the chain rule.

#### duke_nemmerle

$$y=xe^{-x^2}$$

i have no i dea how to start.
$$f'= x^{x^2} or -2x^blah blah blah$$

just get me started and i'll promise you i will finish it myself
You will probably want to use the product rule and the rule for finding the derivative of $$e^{g(x)}$$

#### rocomath

Product rule!!!

$$f(x)=e^{-x^2}$$

derivative of e is itself, times the derivative of it's exponent.

#### rocomath

wow 3 replies all at 22:49 ... you just got the royal treatment :D

#### Feldoh

wow 3 replies all at 22:49 ... you just got the royal treatment :D
ROFL:rofl:

#### Dick

Homework Helper
Start with the product rule. When you get to needing to find d/dx(e^(-x^2)) then remember the chain rule says (f(g(x)))'=f'(g(x))*g'(x). f is exp. g(x)=-x^2. So?

Solved it
thanks

#### Dick

Homework Helper
Geez. I'm really late.

#### physicsed

$$Y'= e^{-x2}(1-2x^{2})$$
thanks for the help

Looks right^^

### The Physics Forums Way

We Value Quality
• Topics based on mainstream science
• Proper English grammar and spelling
We Value Civility
• Positive and compassionate attitudes
• Patience while debating
We Value Productivity
• Disciplined to remain on-topic
• Recognition of own weaknesses
• Solo and co-op problem solving