I am in a Systems and Vibrations class but am currently doing differential equations.(adsbygoogle = window.adsbygoogle || []).push({});

A problem I am doing requires me to find the transfer function [X(s)/F(s)] and compute the characteristic roots.

So far I have:

X(s)/F(s) = (6s +4)/(s^2+14s+58)

That is the transfer function but now i have to find the roots.

I realize I only concern myself with the s^2+14s+58 part and set it equal to 0.

I can't factor it because of obvious reasons. I tried the quadratic equation but my calculator says its a non-real result which means its complex.

My problem is that I cant figure out how to do the quadratic when there is a complex root.

I know as^2 + bs + c = a[(s + sigma)^2 + omega^2] = 0.

However, I cant figure out how to find the roots using this equation.

Cany anyone help me with this?

Thanks,

Mike

**Physics Forums | Science Articles, Homework Help, Discussion**

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!

# Homework Help: Help with finding roots for transfer functions

**Physics Forums | Science Articles, Homework Help, Discussion**