# 領域上の積分

 In[1]:= XIntegrate[1, {x, y} \[Element] Circle[{1, 2}, r]]
 Out[1]=
 In[2]:= XIntegrate[1, {x, y, z} \[Element] Line[{{0, 0, 0}, {1, 1, 1}}]]
 Out[2]=

 In[3]:= XIntegrate[1, {x, y} \[Element] Disk[]]
 Out[3]=
 In[4]:= XIntegrate[1, {x, y, z} \[Element] Sphere[]]
 Out[4]=

 In[5]:= XIntegrate[1, {x, y, z} \[Element] Ball[]]
 Out[5]=
 In[6]:= XIntegrate[1, {x, y, z} \[Element] Tetrahedron[]]
 Out[6]=

 In[7]:= XIntegrate[\!\( \*SubsuperscriptBox[\(x\), \(1\), \(2\)]\ \*SubsuperscriptBox[\(x\), \(2\), \(2\)]\ \*SubsuperscriptBox[\(x\), \(3\), \(2\)]\ \*SubsuperscriptBox[\(x\), \(4\), \(2\)]\ \*SubsuperscriptBox[\(x\), \(5\), \(2\)]\), {Subscript[x, 1], Subscript[x, 2], Subscript[x, 3], Subscript[x, 4], Subscript[x, 5]} \[Element] Ball[{0, 0, 0, 0, 0}, r]]
 Out[7]=

 In[8]:= XIntegrate[Norm[x], x \[Element] Ball[{0, 0, 0, 0, 0}]]
 Out[8]=
 In[9]:= XIntegrate[ Norm[{Subscript[x, 1], Subscript[x, 2], Subscript[x, 3], Subscript[x, 4], Subscript[x, 5]}], {Subscript[x, 1], Subscript[x, 2], Subscript[x, 3], Subscript[x, 4], Subscript[x, 5]} \[Element] Ball[{0, 0, 0, 0, 0}]]
 Out[9]=

あらゆる領域上で積分する．