Worked problem · Calculus I · Unit 2A

Quotient Plus Chain Rule: Worked Example and Solution

A complete quotient plus chain example with method choice, derivation, verification, and a common wrong approach.

1 problem8 min estimated timeFoundational to advanced progression

Problem

  1. Differentiate y=lnxx2y=\frac{\ln x}{x^2}.

Complete worked solutions

Every problem has a source-matched answer and independently reviewed derivation.

01

Problem 1: Differentiate y=lnxx2y=\frac{\ln x}{x^2}.

Answer: y=12lnxx3y'=\frac{1-2\ln x}{x^3}

Why this method: quotient plus chain matches the mathematical structure before any algebraic cleanup.

  1. Apply the quotient plus chain structure before simplifying.
  2. Retain every factor contributed by an inner derivative.
  3. A factored final form is 12lnxx3\frac{1-2\ln x}{x^3}.
  4. Therefore the result is y=12lnxx3y'=\frac{1-2\ln x}{x^3}.

What is included

See a concise answer and full derivation for differentiate y equals natural log x over x squared.

Skills assessed

  • quotient plus chain

Prerequisites

  • basic derivative rules
  • function composition

Common errors

  • Applying the chain rule to a product or quotient as if it were one composition.