Question:medium

If \( y = e^{2x} \), then find \( \dfrac{dy}{dx} \).

Show Hint

For any exponential function of the form \( y = e^{f(x)} \), its derivative is always the original function multiplied by the derivative of the exponent.
That is, \( y' = f'(x) \cdot e^{f(x)} \).
This shortcut allows you to write down the answer instantly for any composite exponential function.
Updated On: Jun 3, 2026
  • \( 2e^{2x} \)
  • \( e^x \)
  • \( 2xe^{2x} \)
  • \( e^{2x}+2 \)
Show Solution

The Correct Option is A

Solution and Explanation

Step 1: Understanding the Concept:
This problem requires finding the derivative of a composite exponential function where the power component is itself a distinct function of $x$. To correctly differentiate a composite function of the form $f(g(x))$, we must use the Chain Rule from differential calculus.
Step 2: Key Formula or Approach:
- The derivative of the baseline natural exponential function $e^u$ with respect to its variable $u$ is itself: $$ \frac{d}{du}(e^u) = e^u $$ - The Chain Rule dictates that if a variable $y$ depends on $u$, which in turn depends on $x$, then: $$ \frac{dy}{dx} = \frac{dy}{du} \cdot \frac{du}{dx} $$ Consequently, the derivative rule for an exponential function containing a linear function in its power is $\frac{d}{dx}(e^{ax}) = a e^{ax}$.
Step 3: Detailed Explanation:
We are given the exponential function: $$ y = e^{2x} $$ Let's define the inner exponent function as a temporary variable $u$: $$ u = 2x $$ This substitution allows us to express our main function as $y = e^u$. Now we differentiate both components separately: 1. Differentiate the outer function $y$ with respect to our inner variable $u$: $$ \frac{dy}{du} = \frac{d}{du}(e^u) = e^u $$ 2. Differentiate our inner function $u$ with respect to the primary variable $x$: $$ \frac{du}{dx} = \frac{d}{dx}(2x) = 2 $$ Finally, apply the Chain Rule formula by computing the product of these two derivatives: $$ \frac{dy}{dx} = \frac{dy}{du} \cdot \frac{du}{dx} = e^u \cdot 2 = 2e^u $$ Substituting our original expression for $u$ ($u = 2x$) back into the equation yields: $$ \frac{dy}{dx} = 2e^{2x} $$ This result corresponds precisely to choice (A).
Step 4: Final Answer:
The derivative $\frac{dy}{dx}$ is equal to $2e^{2x}$.
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