Homework 14

Julia Ferris

2024-05-02

Assignment: For each function, work out some Taylor Series expansions of popular functions. Only consider its valid ranges as indicated in the notes when you are computing the Taylor Series expansion.

Question 1:

\(f(x) = \frac {1} {1 - x}\)

The bounds for this case are when the absolute value of x is less than 1. This means the range is when x is between -1 and 1, excluding the end points.

The Taylor Series for this function is \(\sum_{n=0}^{\infty} x^n\)

The expansion for this is below:

\(1 + x + x^2 + x^3 + x^4 + . . .\)

Question 2:

\(f(x) = e^x\)

The bounds for this case are limitless. All real numbers of x are included in this Taylor series.

The Taylor Series for this function is \(\sum_{n=0}^{\infty} \frac{1}{n!} x^n\)

The expansion for this is below:

\(1 + x + \frac{1}{2}x^2 + \frac{1}{6}x^3 + \frac{1}{24}x^4 + . . .\)

Question 3:

\(f(x) = ln(1 + x)\)

The bounds for this case are x greater than -1 to x less than or equal to 1.

The Taylor Series for this function is \(\sum_{n=1}^{\infty} \frac{(-1)^{n+1}x^n}{n}\)

The expansion for this is below:

\(x + -\frac{x^2}{2} + \frac{x^3}{3} + -\frac{x^4}{4} + . . .\)

Question 4:

\(f(x) = x^{\frac{1}{2}} = \sqrt x\)

The bounds for this case are x greater than 0.

The Taylor Series for this function is \(\sum_{n=0}^{\infty} \frac{f^{(n)}(a)}{n!}(x - a)^n\)

An example of this is below for a center at x = 0:

\(0 + \frac{1}{2}x + -\frac{1}{8}x^2 + \frac{1}{16}x^3 + . . .\)