(Laughter) finding imaginary solutions to quadratic equations.

（笑声）寻找二次方程的虚解。

Which you probably recognize as a quadratic equation.

你可能认为这是一个二次方程。

Practice using the formula by solving quadratic equations.

通过求解二次方程练习使用公式。

To solve the quadratic equation we have to use the quadratic formula.

要求解二次方程， 我们必须使用二次公式。

And you may even have learned a little bit about the quadratic equation.

您甚至可能对二次方程有所了解。

And we end up with this. Which you probably recognize as a quadratic equation.

我们最终得到了这个。 你可能认为这是一个二次方程。

That question about the plots of land can be written as one of the first equations with unknowns you probably ever heard of, the quadratic equation.

关于土地的问题可以写成最早的未知数方程之一，你可能听说过，二次方程。

Set up a spaced repetition schedule: Day 1, Day 4, Day 11, Day 25, etc. Review and practice by solving various quadratic equations during each session.

设置一个间隔重复的时间表：第 1 天、第 4 天、第 11 天、第 25 天等。通过在每个会话期间求解各种二次方程来复习和练习。