Derivatives: rules and functions

Chain rule

The chain rule, {f(g(x))}′=f′(g(x)) g′(x)\{f(g(x))\}'=f'(g(x))\,g'(x), differentiates the outside and multiplies by the derivative of the inside.

{f(g(x))}′=f′(g(x)) g′(x)\{f(g(x))\}'=f'(g(x))\,g'(x)

Differentiate the outer function while leaving the inside as it is, then multiply by the derivative of the inside.

{(2x+1)5}′=5(2x+1)4⋅2=10(2x+1)4\begin{gathered} \{(2x+1)^5\}' \\[4pt] =5(2x+1)^4\cdot 2 \\[4pt] =10(2x+1)^4 \end{gathered}

Forgetting that inner factor is the classic mistake.

Examples

  1. 01Differentiateddx cos⁡(5x5)\displaystyle \frac{d}{dx}\,\cos(5 x^{5})AnswerHide
    Answer−25x4sin⁡(5x5)\displaystyle -25x^{4} \sin(5 x^{5})
  2. 02Differentiateddx log⁡e(x2)\displaystyle \frac{d}{dx}\,\log_e(x^{2})AnswerHide
    Answer2x\displaystyle \frac{2}{x}
  3. 03Differentiateddx e2x2\displaystyle \frac{d}{dx}\,e^{2 x^{2}}AnswerHide
    Answer4xe2x2\displaystyle 4x e^{2 x^{2}}
  4. 04Differentiateddx ex4\displaystyle \frac{d}{dx}\,e^{x^{4}}AnswerHide
    Answer4x3ex4\displaystyle 4x^{3} e^{x^{4}}
  5. 05Differentiateddx (3cos⁡x)3\displaystyle \frac{d}{dx}\,(3 \cos x)^{3}AnswerHide
    Answer−9(3cos⁡x)2sin⁡x\displaystyle -9 (3 \cos x)^{2} \sin x
  6. 06Differentiateddx (log⁡ex)5\displaystyle \frac{d}{dx}\,(\log_e x)^{5}AnswerHide
    Answer5(log⁡ex)4x\displaystyle \frac{5 (\log_e x)^{4}}{x}

FAQ

What is easy to forget with the chain rule?
Multiplying by the derivative of the inside. For (2x+1)5(2x+1)^5, take 5(2x+1)45(2x+1)^4 and multiply by 2 to get 10(2x+1)410(2x+1)^4.

Published 2026-09-03 · Updated 2026-09-05