Four operations and derivative operations of MATLAB polynomials

MATLAB Four operations of polynomials and derivative operations

1. Addition and subtraction operations can be performed directly through "+“ and ”-" To achieve , Different orders , Lower order polynomials must use 0 To fill
2. Multiplication passes conv Function implementation , This function is equivalent to finding the convolution of two arrays
   for example ： Find a polynomial x³+2x²+3x+4 With the polynomial x²+2x+3 Multiply , The code is as follows ：

   p1 = [1 2 3 4];
   p2 = [1 2 3];
   p3 = conv(p1,p2);   % Get the coefficient of polynomial multiplication 
   multinomial = poly2sym(p3);	    % Find the polynomial according to the coefficient 
   

   The results obtained are as follows ：
   
3. For division operation, you can pass deconv Function implementation , Equivalent to deconvolution

% Function description 
[s,r] = deconv(p,q)    
%p： Divisible form 
%q： Division 
%s： merchant 
%r： The rest of the formula 

for example ： Find a polynomial x³+2x²+3x+4 With the polynomial x²+2x+3 be divided by , The code is as follows ：

 p1 = [1 2 3 4];
 p2 = [1 2 3];
 [s,r] = deconv(p1,p2);   % Obtain the quotient and remainder after the division of polynomials 

The results are as follows ：

4. For the derivative operation of polynomials, you can use polyder Function implementation
   for example ：

p = [1 2 3 4];
a = poly2sym(p)
b = poly2sym(polyder(p))   

The results are shown below ：