Hey, I'm going over series expansions and was wondering if someone could check my work and tell me if my work is correct. If not, could you explain it to me? I couldn't find any example like this problem in my book so I'm posting it online. Here it is,(adsbygoogle = window.adsbygoogle || []).push({});

The closed form series expansion for cos(x) is Ʃ[(-1)^n(x)^2n]/(2n)!. Use this series to find a series expression for [cos(x)-1]/x^2.

Okay here's what I did:

[cos(x)-cos(pi)]/(x)^(2)

(x)^(-2)*Ʃ[(-1)^(n)(x)^(2n)-(pi)^(2n)]/(2n)!

Ʃ[(-1)^(n)(x)^(2n-2)-(pi)^(2n)

Is that the way I'm supposed to do it? Thanks!

**Physics Forums - The Fusion of Science and Community**

Join Physics Forums Today!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

# Series expression

Loading...

Similar Threads - Series expression | Date |
---|---|

I Help with simplifying series of hyperbolic integrals | Nov 19, 2017 |

I Taylor series | Jul 21, 2017 |

I How to understand Taylor/Mclaurin series? | May 19, 2017 |

I Find the formula to express the infinite series... | Jun 27, 2016 |

Expressing a function as a power series | Aug 15, 2013 |

**Physics Forums - The Fusion of Science and Community**