Use Mu ̈ller’s method to determine the real and complex roots of
f (x) = x^4 − 2x^3 + 6x^2 − 2x + 5
1
Expert's answer
2020-11-05T13:56:49-0500
Let f(x)=x4−2x3+6x2−2x+5
Use initial guesses x0=−1,x1=0,x2=1
f(x0)=f(−1)=16
f(x1)=f(0)=5
f(x2)=f(1)=8
h0=x1−x0=0−(−1)=1
h1=x2−x1=1−0=1
δ0=h0f(x1)−f(x0)=15−16=−11
δ1=h1f(x2)−f(x1)=18−5=3
a=h1+h0δ1−δ0=1+13−(−11)=7
b=a×h1+δ1=7×1+3=10
c=f(x2)=f(1)=8
x3=x2+b±b2−4ac−2c
x3=1+10+102−4(7)(8)−2(8)==0.285714+0.795395i
x0=−1,x1=0,x2=0.285714+0.795395i
Calling the function Muller with different parameters yields two complex roots of the equation x1≈i,x3≈1+2i. Two other roots can be determined as their conjugate pairs x2≈−i,x4≈1−2i.
Comments