Calculus I — Lecture Notes (Limits &
Derivatives)
Prepared for: Undergraduate Calculus — Week 1
Contents
1. Limits — definition and techniques
2. Continuity
3. Derivative — definition and interpretation
4. Rules of differentiation
5. Worked examples
6. Practice problems (with answers)
1. Limits — definition
Limit of f(x) as x approaches a is the value L that f(x) approaches as x gets arbitrarily close to a.
Notation: \(\lim_{x\to a} f(x) = L\).
Techniques: algebraic simplification, factoring, rationalization, squeeze theorem.
3. Derivative — definition and interpretation
The derivative f'(x) is the instantaneous rate of change: \(f'(x)=\lim_{h\to0}\frac{f(x+h)-f(x)}{h}\).
Geometrically, slope of tangent.
Common rules: constant rule, power rule, sum rule, product rule, quotient rule, chain rule.
5. Worked examples
Example 1: Differentiate f(x) = 3x^4 - 5x + 7
Solution: f'(x)=12x^3 - 5.
Example 2: Differentiate g(x) = (2x^3)(sin x)
Solution: Product rule: g' = 6x^2 sin x + 2x^3 cos x.
Example 3: Find \(\lim_{x\to2}\frac{x^2-4}{x-2}\).
Solution: Factor numerator: (x-2)(x+2)/(x-2) = x+2; limit = 4.
6. Practice problems (answers on next page)
1. Compute derivative of f(x) = x^5 - 4x^2 + 3x - 1
2. Evaluate \(\lim_{x\to0}\frac{\sin x}{x}\)
3. Differentiate h(x) = e^{2x} * x^2
Answers
1. 5x^4 - 8x + 3
2. 1
3. h' = 2e^{2x}x^2 + 2x e^{2x} = 2xe^{2x}(x+1)
End of Calculus I notes — concise 2-page study pack.