Coefficients of a polynomial: coeff coeffs

### 2.24.3 Coefficients of a polynomial: `coeff coeffs`

`coeff` or `coeffs` takes three arguments : the polynomial, the name of the variable (or the list of the names of variables) and the degree (or the list of the degrees of the variables).
`coeff` or `coeffs` returns the coefficient of the polynomial of the degree given as third argument. If no degree was specified, `coeffs` return the list of the coefficients of the polynomial, including 0 in the univariate dense case and excluding 0 in the multivariate sparse case.
Input :

`coeff(-x```^```4+3*x*y```^```2+x,x,1)`

Output :

`3*y```^```2+1`

Input :

`coeff(-x```^```4+3x*y```^```2+x,y,2)`

Output :

`3*x`

Input :

`coeff(-x```^```4+3x*y```^```2+x,[x,y],[1,2])`

Output :

`3`