AP Calculus BC

Advanced Placement Calculus BC including series, parametric equations, and polar functions.

Basic Concepts

Power Series and Taylor Series

Power Series: Functions as Infinite Sums

A power series expresses a function as an infinite sum of powers of \(x\):

\[ f(x) = a_0 + a_1(x-c) + a_2(x-c)^2 + \cdots \]

The most famous power series are Taylor and Maclaurin series, which help us approximate functions like sine, cosine, and exponential.

Taylor Series

The Taylor series for a function \(f(x)\) centered at \(c\):

\[ f(x) = f(c) + f'(c)(x-c) + \frac{f''(c)}{2!}(x-c)^2 + \cdots \]

If \(c = 0\), it's called a Maclaurin series.

Why Use Power Series?

Power series can approximate complicated functions and are used in everything from calculators to computer graphics and scientific modeling.

Real-World Use

  • Engineers use Taylor series to design circuits and solve physics problems.
  • Programmers use them for fast function calculations.

Examples

  • The Maclaurin series for \(e^x\) is \(1 + x + x^2/2! + x^3/3! + \cdots\).

  • The sine function can be written as \(x - x^3/3! + x^5/5! - \cdots\).

In a Nutshell

Power and Taylor series turn complex functions into infinite sums for easier calculation and estimation.