# How to plot a polynomial of which I have coefficient vector?

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Luigi Treccozzi on 30 Jan 2018
I have only coefficient: how to plot it?

madhan ravi on 31 Jan 2019
fplot(poly2sym(a)) % where a is coefficients of a polynomial

Walter Roberson on 31 Jan 2019
t = linspace(-10,10); %adjust as needed
plot(t, polyval(a, t)); % where a is coefficients of a polynomial

Jyotish Robin on 8 Feb 2018
Hi Luigi,
Hopefully, the command 'fplot' can be helpful. For example,
a=[1 2 3]; % coefficients
fplot(@(x) a(1)*x+ a(2)*(x .^2)+a(3)*(x.^3))
will plot a polynomial function in x.
Hope this helps!
Thanks,
Jyotish

Timothy Simon Thomas on 3 Jun 2020
Edited: Timothy Simon Thomas on 3 Jun 2020
Config
s=10
t=[-s:0.00001:s];
x=t;
Parameters
a=1
b=-6
c=11
d=-6
Equation
fx=(a*(x.^3)) + (b*(x.^2)) + (c.*x) + d;
syms x1
fx1=(a*(x1.^3)) + (b*(x1.^2)) + (c.*x1) + d;
solve(fx1==0,x1)
Plotting
plot(t,fx)
axis([-s,s,-s^2,s^2])
Draw Axes
line([0 0],[-s^2 s^2])
line([-s s],[0 0])
title('Cubic and lower Polynomial Visualiation')