Introduction to Analysis

An introductory course that explores the fundamental concepts and techniques of mathematical analysis.

Advanced Topics

The Concept of the Derivative

What Is a Derivative?

The derivative measures how a function changes as its input changes. It's like asking, "How fast is my position changing at this exact moment?"

The Formal Definition

The derivative of \( f \) at \( x \) is: \[ f'(x) = \lim_{h \to 0} \frac{f(x + h) - f(x)}{h} \] It tells us the instantaneous rate of change.

Tangent Lines and Slopes

The derivative at a point gives the slope of the tangent line to the function's graph at that point.

Why Derivatives Matter

Derivatives help us understand motion, optimize designs, and solve countless problems in science and engineering!

Key Formula

\[f'(x) = \lim_{h \to 0} \frac{f(x+h) - f(x)}{h}\]

Examples

  • If \( f(x) = x^2 \), then \( f'(x) = 2x \).

  • The derivative of \( f(x) = \sin x \) is \( \cos x \).

In a Nutshell

The derivative tells us how a function is changing at any instant — its rate of change.

Key Terms

Derivative
The limit that describes the instantaneous rate of change of a function.
Tangent Line
A straight line that touches a curve at one point without crossing it.