9 微分方程简介 (1)把下列各组的单词、词组与短语译成英语,并按它们的相关性联想记忆: (请把答案分两列,左列为汉语,右列为对应的英语) 微分方程 可微的 指数函数 初始条件 初值问题 对...积分 对数函数 力学 常微分方程 被积函数 (2) 汉译英: (请先在答案中粘贴下列的汉语原文) 大量的科学问题需要人们根据事物的变化率去确定某些量。 (3): (请在答案中先粘贴下列英语原文) The quadratic equation x^2 + 1 = 0 has no solution in the real-number system because there is no real number whose square is -1. New types of numbers, called complex numbers, have been introduced to provide to solutions to such equation. In this brief chapter we discuss complex number and show that they are important in solving algebraic equations and that they have an impact on differential and integral calculus.