asked 92.2k views
1 vote
Find a power series for the function, centered at c.

g(x)=
x
2
+2x−3
4x

,c=0
g(x)=∑
n=0
[infinity]



Determine the interval of convergence. (Enter your answer using interval notation.)

1 Answer

5 votes

Answer:

To find the power series representation of the function g(x) centered at c=0, we can expand it as a sum of terms involving powers of (x - 0), which simplifies to x. We'll also simplify the expression:

g(x) = x^2 + 2x - 3 / (4x)

To express g(x) as a power series, we'll focus on the term (2x - 3) / (4x) and expand it separately. We can rewrite it as:

(2x - 3) / (4x) = (1/2) * (x - 3/2x)

Now we'll use the power series representation of (1 - a)^(-1), which is valid for |a| < 1. In our case, a = -3/2x, so we have:

(2x - 3) / (4x) = (1/2) * [1 - (-3/2x)]^(-1)

Expanding this using the power series representation, we get:

(2x - 3) / (4x) = (1/2) * [1 + (-3/2x) + (-3/2x)^2 + (-3/2x)^3 + ...]

Simplifying further:

(2x - 3) / (4x) = (1/2) + (-3/4x) + (9/8x^2) + (-27/16x^3) + ...

Now let's combine this with the x^2 term:

g(x) = x^2 + (1/2) + (-3/4x) + (9/8x^2) + (-27/16x^3) + ...

This is the power series representation of g(x) centered at c=0.

To determine the interval of convergence, we need to find the values of x for which the series converges. In this case, we observe that the power series involves negative powers of x, so it converges when x ≠ 0.

Therefore, the interval of convergence is (-∞, 0) ∪ (0, +∞) (excluding 0), expressed in interval notation.

answered
User Perumer
by
8.1k points
Welcome to Qamnty — a place to ask, share, and grow together. Join our community and get real answers from real people.