Use MATLAB to carry out the following multiplication of poly

Use MATLAB to carry out the following multiplication of polynomials: x(x - 1.7) (x + 0.5) (x - 0.7) (x + 1.5)

Solution

Multiplication of polynomial can be a very dreary task, so do division of polynomial. Matlab use the functions conv and deconv to help you do these tasks with the least commotion possible, and most importantly with the assurance to find the right result the quickest way possible.

x(x-1.7)(x+0.5)(x-0.7)(x+1.5)=(x²-1.7x)(x+0.5)(x-0.7)(x+1.5)

s=[1 -1.7]

t=[ 1 0.5]

s =

1.0000 -1.7000

t =

1.0000 0.5000

>> conv(s,t)

ans =

1.0000 -1.2000 -0.8500

v=[1 -1.2 -0.85]

k=[1 0.7 ]

conv=(v,k)

v=[1 -1.2 -0.8]

v =

1.0000 -1.2000 -0.8000

>> k=[1 0.7]

k =

1.0000 0.7000

>> conv(v,k)

ans =

1.0000 -0.5000 -1.6400 -0.5600

w=[1 -0.5 -1.64 -0.56]

w =

1.0000 -0.5000 -1.6400 -0.5600

>> d=[1 1.5]

d =

1.0000 1.5000

>> conv(w,d)

ans =

1.0000 1.0000 -2.3900 -3.0200 -0.8400

the multiplication polynominal is x⁴+x³-2.39x²-3.02x-0.84