Naar aanleiding van Goniometrische vergelijking had ik zoiets:
$
\eqalign{
& \cos \left( {2\pi t} \right) = \cos \left( {\frac{1}
{6}\pi t} \right) \cr
& 2\pi t = \frac{1}
{6}\pi t + k \cdot 2\pi \vee 2\pi t = - \frac{1}
{6}\pi t + k \cdot 2\pi \cr
& 1\frac{5}
{6}\pi t = k \cdot 2\pi \vee 2\frac{1}
{6}\pi t = k \cdot 2\pi \cr
& t = k \cdot \frac{{12}}
{{11}} \vee t = k \cdot \frac{{12}}
{{13}} \cr}
$
$
\eqalign{t = 0 \vee t = \frac{{12}}
{{13}} \vee t = \frac{{12}}
{{11}} \vee t = 1\frac{11}
{{13}} \vee t = \,2\frac{2}
{{11}} \vee t = \,2\frac{{10}}
{{13}}}
$