2 sentences

1. 这是一个非线性方程。

   zhè shì yī gè fēi​xiàn​xìng fāng​chéng.

   This is a non-linear equation.

   Source: Dong Chinese Dictionary

2. 该非线性方程在临界点产生了分歧。

   gāi fēi​xiàn​xìng fāng​chéng zài lín​jiè​diǎn chǎn​shēng le fēn​qí.

   The nonlinear equation bifurcates at the critical point.

   Source: Dong Chinese Dictionary