Lesson 22.4

The Fundamental Theorem of Calculus Preview

A concluding conceptual increment explaining that derivatives and integrals are inverse operations.

Introduction

The Fundamental Theorem of Calculus (FTC) is one of the most important results in all of mathematics. It connects the two main ideas of calculus: differentiation (finding rates of change) andintegration (finding accumulations). They are inverses of each other!

1

Prerequisite Connection

You understand derivatives and Riemann sums as limits.

2

Today's Increment

We see how differentiation and integration undo each other.

3

Why This Matters

The FTC makes computing integrals practical—it's the key to applied calculus.

Key Concepts

FTC Part 1: Integration then Differentiation

If you integrate then differentiate, you get back to the original function.

FTC Part 2: Differentiation then Integration

If you integrate a derivative, you get the net change in the original function.

The Practical Result

Where F is ANY antiderivative of f (F' = f).

The Big Picture

Differentiation and Integration are inverse operations, like addition/subtraction or multiplication/division.

Worked Examples

Example 1: Inverse Relationship (Basic)

If , find an antiderivative F(x).

We need F where F'(x) = x²

Since

Example 2: Using FTC to Evaluate (Intermediate)

Evaluate

Antiderivative of 2x is x²

Area = 8

Example 3: Net Change Interpretation (Advanced)

If velocity , find net displacement from t = 0 to t = 2.

Displacement = 8 units

Common Pitfalls

Forgetting the constant

Indefinite integrals need "+C". Definite integrals don't.

Wrong order of evaluation

F(b) - F(a), NOT F(a) - F(b). Upper minus lower!

Real-World Application

Engineering and Physics

The FTC connects rate of change (velocity, acceleration, power) to accumulation (position, velocity, energy). Engineers use it constantly to go between these perspectives!

Position ↔ Velocity ↔ Acceleration

Connected by differentiation and integration

Practice Quiz

Loading...

🎉 Congratulations!

You've completed the Precalculus course! You now have the conceptual foundation for Calculus: limits, derivatives, and integrals. You're ready to dive deeper into the techniques and applications of calculus.