Nếu f(x) là hàm tuần hoàn với chu kì T thì:

\[\mathop \smallint \limits_{\rm{a}}^{{\rm{a + T}}} {\rm{f(x)dx}} = - \mathop \smallint \limits_0^{\rm{a}} {\rm{f(x)dx}}\]

\[\mathop \smallint \limits_{\rm{a}}^{{\rm{a + T}}} {\rm{f(x)dx}} = \mathop \smallint \limits_0^{\rm{a}} {\rm{f(x)dx}}\]

\[\mathop \smallint \limits_{\rm{a}}^{{\rm{a + T}}} {\rm{f(x)dx}} = 0\]

\[\mathop \smallint \limits_{\rm{a}}^{{\rm{a + T}}} {\rm{f(x)dx}} = - \mathop \smallint \limits_T^{\rm{a}} {\rm{f(x)dx}}\]