### 2.24.6 Leading coefficient of a polynomial : `lcoeff`

`lcoeff` takes as argument a polynomial given by a
symbolic expression or by the list of it’s coefficients.

`lcoeff` returns the leading coefficient of this polynomial,
that is the coefficient of the monomial of highest degree.

Input :

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

Output :

`2`

Input :

`lcoeff(3*x``^`

`2+5*x,x)`

Output :

`3`

Input :

`lcoeff(3*x``^`

`2+5*x*y``^`

`2,y)`

Output :

`5*x`