Dot

a.b computes the product of a and b for vectors and matrices.

Attributes[Dot] := {Flat, OneIdentity, Protected}

Simple examples

In[1]:= Dot[{a, b}, {c, d}]
Out[1]= a*c + b*d

In[2]:= Dot[{a, b}, {c, d, e}]
Out[2]= Dot[{a, b}, {c, d, e}]

In[3]:= Dot[1, {c, d, e}]
Out[3]= Dot[1, {c, d, e}]

In[4]:= Dot[{}, {}]
Out[4]= 0

In[5]:= Dot[{{a, b}, {c, d}}, {e, f, g}]
Out[5]= Dot[{{a, b}, {c, d}}, {e, f, g}]

In[6]:= Dot[{a, b}]
Out[6]= {a, b}

In[7]:= Dot[a]
Out[7]= a

In[8]:= Dot[1]
Out[8]= 1

In[9]:= Dot[{{a, b}, {c, d}}, {{e, f}, {g, h}}]
Out[9]= {{a*e + b*g, a*f + b*h}, {c*e + d*g, c*f + d*h}}

In[10]:= Dot[{{a, b}, {c, d}}, {{e}, {f}}]
Out[10]= {{a*e + b*f}, {c*e + d*f}}

In[11]:= Dot[{{a, b}, {c, d}}, {{e, f}}]
Out[11]= Dot[{{a, b}, {c, d}}, {{e, f}}]