Trailing coefficient degree of a polynomial : tcoeff

### 2.24.7 Trailing coefficient degree of a polynomial : `tcoeff`

`tcoeff` takes as argument a polynomial given by a symbolic expression or by the list of its coefficients.
`tcoeff` returns the coefficient of the monomial of lowest degree of this polynomial (`tcoeff`=trailing coefficient).
Input :

`tcoeff([2,1,-1,0])`

Output :

`-1`

Input :

`tcoeff(3*x```^```2+5*x,x)`

Output :

`5`

Input :

`tcoeff(3*x```^```2+5*x*y```^```2,y)`

Output :

`3*x```^```2`