Re

In[1]:= Re[1]
Out[1]= 1

In[2]:= Re[0.5]
Out[2]= 0.5

In[3]:= Re[(2)/(3)]
Out[3]= (2)/(3)

In[4]:= Re[2 + I]
Out[4]= 2

In[5]:= Re[(1*E^(I*(Pi)/(4)))/(2)]
Out[5]= (1)/(2*Sqrt[2])

In[6]:= Re[foo + 1]
Out[6]= 1 + Re[foo]

In[7]:= Re[foo + 1 + bar]
Out[7]= 1 + Re[foo + bar]

In[8]:= Re[foo + I]
Out[8]= Re[foo]

In[9]:= Re[foo + I + bar]
Out[9]= Re[foo + bar]

In[10]:= Re[(a)/(2)]
Out[10]= (Re[a])/(2)