Lesson 13: Optimization – Finding Maximum & Minimum Values

1. What is Optimization?

Optimization finds maximum or minimum values of a function — very common in real life and ML.

Examples:

Key idea: at max/min points, the derivative (slope) is zero.

2. Steps for Optimization

  1. Define the function to optimize (objective function)
  2. Express in terms of one variable (if needed)
  3. Find critical points: set \(f'(x) = 0\) and solve
  4. Use second derivative test or first derivative test to classify:
    • \(f''(x) > 0\) → local minimum
    • \(f''(x) < 0\) → local maximum
    • \(f''(x) = 0\) → inconclusive
  5. Check endpoints if domain is closed interval

Exercise 1

For \(f(x) = x^3 - 3x^2 + 2x\) on \([-1, 3]\), find critical points:
\(f'(x) =\) \(x^2 -\) \(x +\) \(= 0\)

Exercise 2

A rectangle has perimeter \(40\) cm. Maximize area. What is the derivative set to zero?

Summary – Lesson 13

Next: curve sketching using derivatives.

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