Q. \[ \frac{d}{dx}\left(e^{-x}\right) \]
Answer
To differentiate \(e^{-x}\), use the chain rule.
Let the inside function be \(u=-x\). Then \( \frac{d}{dx} e^{u} = e^{u}\cdot \frac{du}{dx}\).
\(\frac{du}{dx} = -1\), so
\[
\frac{d}{dx}\left(e^{-x}\right)=e^{-x}\cdot (-1)=-e^{-x}.
\]
Final result: \(-e^{-x}\).
Detailed Explanation
We want to find the derivative of the function
\[
f(x)=e^{-x}.
\]
Step 1: Identify the outside function and the inside function (Chain Rule).
The Chain Rule applies to compositions of the form \(f(g(x))\).
Here:
-
The outside function is \(e^{u}\).
-
The inside function is \(u=-x\).
So we can rewrite \(e^{-x}\) as \(e^{u}\) where \(u=-x\).
Step 2: Differentiate the outside function.
The derivative of \(e^{u}\) with respect to \(u\) is
\[
\frac{d}{du}\left(e^{u}\right)=e^{u}.
\]
Step 3: Differentiate the inside function.
The inside function is \(u=-x\), so
\[
\frac{d}{dx}(-x)=-1.
\]
Step 4: Apply the Chain Rule.
The Chain Rule says:
\[
\frac{d}{dx}\left(e^{u}\right)=e^{u}\cdot \frac{du}{dx}.
\]
Substitute \(u=-x\):
\[
\frac{d}{dx}\left(e^{-x}\right)=e^{-x}\cdot(-1).
\]
Step 5: Simplify.
\[
\frac{d}{dx}\left(e^{-x}\right)=-e^{-x}.
\]
Final Answer:
\[
\frac{d}{dx}\left(e^{-x}\right)=-e^{-x}.
\]
Graph
Calculus FAQ
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