Resultant
 Usage
• Resultant[ ,  , var] 关于变量 var计算多项式  和  的结式. • Resultant[ ,  , var, Modulus->p] 计算模素数 p的结式.
Notes
• 首项系数都为1的两个多项式  和  的结式是多项式根之间所有差分  的乘积. 结式总是一个数或多项式.
 Further Examples
Here is the resultant with respect to y of two polynomials in x and y. The original polynomials have a common root in y only for values of x at which the resultant vanishes.
In[1]:=
|
Out[1]=
|
Here Resultant is used to define Discriminant. The discriminant of a polynomial is the product of the squares of all the differences of the roots taken in pairs.
In[2]:=
|
This gives the discriminant for a fifth degree polynomial.
In[3]:=
|
Out[3]=
|
In[4]:=
|
|
