Q. \(\displaystyle \frac{d}{dx}\left(\frac{1}{e^x}\right)\)
Answer
We use \( \frac{d}{dx}\left(e^x\right)=e^x \) and the derivative of an inverse/power.
Rewrite:
\[
\frac{1}{e^x} = e^{-x}
\]
Differentiate:
\[
\frac{d}{dx}\left(e^{-x}\right)=e^{-x}\cdot(-1)=-e^{-x}
\]
Final result:
\[
\frac{d}{dx}\left(\frac{1}{e^x}\right)=-\frac{1}{e^x}
\]
Detailed Explanation
We want to find the derivative of the function
\[
f(x)=\frac{1}{e^x}.
\]
Step 1: Rewrite the function using exponent rules
Recall that
\[
\frac{1}{e^x}=e^{-x}.
\]
So our function can be written as
\[
f(x)=e^{-x}.
\]
Step 2: Differentiate using the chain rule
Recall the derivative rule:
\[
\frac{d}{dx}\left(e^{u(x)}\right)=e^{u(x)}\cdot u'(x).
\]
Here, \(u(x)=-x\). First find \(u'(x)\):
\[
u(x)=-x \quad \Rightarrow \quad u'(x)=-1.
\]
Now differentiate \(f(x)=e^{u(x)}\):
\[
f'(x)=e^{u(x)}\cdot u'(x)=e^{-x}\cdot(-1)=-e^{-x}.
\]
Step 3: Rewrite in the original form (optional)
Since \(e^{-x}=\frac{1}{e^x}\), we can write
\[
f'(x)=-\frac{1}{e^x}.
\]
Final Answer
\[
\boxed{\frac{d}{dx}\left(\frac{1}{e^x}\right)=-\frac{1}{e^x}}
\]
Calculus FAQ
What is \( \frac{d}{dx}\left(\frac{1}{e^x}\right) \)?
Can I use the quotient rule for \( e^{-x} \)?
What is the derivative of \( e^{-x} \) directly?
What is \( \frac{d}{dx}\left(e^x\right) \) and how does it relate?
How do I differentiate \( \frac{1}{e^x} \) using limits?
What is the derivative of \( \frac{1}{e^{2x}} \)?
Use them to solve 1/e^x.
Math, Geometry, Trigonometry, etc.