毕氏定理

例句：

1. 1. This equation is a key to solving the problem of finding the roots of a quadratic equation.
   这个方程是解决二次方程求根问题的关键。
2. 2. The mathematician used this theorem to prove that the sum of two numbers is alwaysgreater than their product.
   这位数学家利用这一定理证明了两个数的和总是大于它们的积。
3. 3. The professor explained the concept of the theorem in his lecture, which was very helpful for understanding complex mathematical concepts.
   教授在他的讲座中解释了这一定理的概念，这有助于理解复杂的数学概念。