 
 
 
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 :
Output :
Input :
^2+5*x,x)Output :
Input :
^2+5*x*y^2,y)Output :
^2 
 
