n.被积式；被积函数

The integrand is the function that is being integrated in a definite integral.
积分是定积分中被积分的函数。
In calculus, we often need to find the integral of an integrand.
在微积分中，我们经常需要找到一个被积函数的积分。
The integrand can be a complex expression involving variables and constants.
被积函数可以是一个涉及变量和常数的复杂表达式。
To evaluate an integral, we must first identify the integrand.
为了计算积分，我们必须首先识别被积函数。
The integrand may be simplified or rewritten before integration.
被积函数在积分前可能被简化或重写。
The integrand can sometimes be expressed as a product of simpler functions.
被积函数有时可以表示为更简单函数的乘积。
The integrand in this case is a polynomial function.
这种情况下，被积函数是一个多项式函数。
The integrand must be continuous over the interval of integration.
被积函数必须在整个积分区间内连续。
The integrand can also be represented graphically to aid in understanding.
被积函数也可以以图形形式表示，以帮助理解。
In some cases, the integrand may not have an elementary antiderivative.
在某些情况下，被积函数可能没有初等原函数。