Question

Use Bairstow’s method to determine the roots of (a) f(x) = -2 + 6.2x -4x^2 + 0.7x^3

b) f(x) = 9.34 - 21.97x +16.3x^2- 3.704x^3

(c) f(x) = x^4- 2x^3 + 6x^2- 2x + 5

I need the the solution for above equation in excel programming.

Answer 1

istorl's m 2. 3 on 7 C 3 roots Na <T - 1.085

Input: >> a=[1-2 6-2 5);tc efficients of given polynomaal toler.1e-2 stopping criterion Pre-loop ops order-length (a)-1:torder of polynomial rootspoly#NaN(order) ;%total q-a ;%for recusion roots of polynomial - %Main loop while order>=3 %i.e. at least 3rd rder p lynamiał [u, v1-bairstow-function (q, toler); fit equation x2+ux+v-0 discr#sqrt(u^2-4"V) ;fd13crımînant of quadratic equation roots poly (order-1:order-udiscr -discr])/2:roots of [q,r)=deconv (g, [1 u v1); order-order-2: quadratic eq end If the order of the polynomial quotient is less than 3 if order<3 if order 1 roots poly (order)-q (2)/q(i) else discr=sqrt (g(2)"2-4"q (1)"q (3) ); roots poly (order-1:order-(a(2) +[discr -discr)/2/q (1): end end bpost processing plot (real (roots poly),imag (roots poly).'o,real (roots (a)).imag (roots (a)), ylabel (Imaginary Part'):xlabel ('real par):grid on: legend (Bairstow method', 'Matlab roots function'