Hey everyone Im doing control engineering and was wondering what methods i could use to find the roots of a 4th order polynomial? For example: (x^4) + (8x^3) + (7x^2) + 6x = 5 Could I seperate that into two brackets of quadratics or will i need to use a really long winded method? Thanks in advance for any help
'order'? You mean 'degree'! Well yes there is a solution for it but it is indeed long winded. You can try to find easy solutions by try. Else use Maple or Matlab.
A formula exists for 4 degree polynomials analogously to the quadratic formula, but it is very long and complicated and coding it into a program would take too much time. Just numerically approximate all the roots.
Sorry, i do mean degree! Slipped up cos im working with a 4th order system. I was worried id have to do it the long way. I did use Matlab but wanted to see if I could work out the answer by hand. Anywat, thanks for the help guys. I really appreciate it!