Interferenz zweier Wellen

\begin{aligned} A(x, t) &= A_1(x, t) + A_2(x, t) \\ A_i(x, t) &= A_i^0 \sin \left( \omega_i t - \frac{2\pi x}{\lambda_i} +\varphi_i \right) \;\; (i = 1, 2) \end{aligned}