Calculus Lecture Notes
Overview
- Newton's Quotient
- Fundamental to understanding derivatives from first principles.
- Used to find the slope or instantaneous rate of change of a function at a specific point.
- Calculate derivative by evaluating the limit as h approaches zero.
- Example: Differentiating ( f(x) = x^2 - 2x + 4 ) and evaluating ( f'(4) ).
Derivative Rules
- Power Rule: ( \frac{d}{dx} x^n = nx^{n-1} )
- Product Rule: ( \frac{d}{dx} [f(x)g(x)] = f'(x)g(x) + f(x)g'(x) )
- Quotient Rule: ( \frac{d}{dx} \frac{f(x)}{g(x)} = \frac{f'(x)g(x) - f(x)g'(x)}{[g(x)]^2} )
- Chain Rule: ( \frac{d}{dx} f(g(x)) = f'(g(x))g'(x) )
Derivatives of Special Functions
- Exponential Functions: ( \frac{d}{dx} b^x = b^x \ln(b) )
- Logarithmic Functions: ( \frac{d}{dx} \log_b(x) = \frac{1}{x \ln(b)} )
- Trigonometric Functions:
- ( \frac{d}{dx} \sin(x) = \cos(x) )
- ( \frac{d}{dx} \cos(x) = -\sin(x) )
- ( \frac{d}{dx} \tan(x) = \sec^2(x) )
First Derivative Test
- Critical Numbers: Points where the first derivative is zero or undefined.
- Test: Classify critical points as local maxima, minima, or neither by analyzing sign changes of the derivative.
Second Derivative Test
- Concavity:
- Positive second derivative indicates concave up.
- Negative second derivative indicates concave down.
- Test: Determine local extrema using the concavity and critical points.
Curve Sketching
- Use derivatives to analyze function behavior:
- Identify intervals of increase/decrease.
- Determine concavity changes and points of inflection.
- Utilize critical points to indicate maxima/minima.
Optimization
- Problem Solving:
- Define objective and constraint functions.
- Utilize first or second derivative tests to find minimum or maximum values.
- Example: Minimize surface area of an open box given volume constraints.
Antiderivatives
- Notation: ( \int f(x) , dx = F(x) + C )
- Methods: Use power rule for integration and substitution techniques.
Definite Integrals
- Applications: Calculate areas under curves.
- Fundamental Theorem of Calculus: Evaluate antiderivative at endpoints.
Calculating Volumes
- Disk Method: Calculate volume of solids of revolution.
- Use definite integrals to sum volumes of infinitesimal disks.
This lecture covered foundational concepts and rules essential to calculus, focusing on differentiation and integration techniques and their applications in problem-solving scenarios.