proportional plus integral plus derivative controller

例句：

1. 1.The proportion of students who passed the exam was 70%.
   通过考试的学生比例是70%。
2. 2.The ratio of male to female students in our class is 3:1.
   我们班男生和女生的比例是3:1。
3. 3. The proportion of sugar in this cake is 15%.
   这个蛋糕中糖的比例是15%。
4. 1. The integral of a function is the sum of all its values at different points.
   一个函数的积分是所有不同点上值的总和。
5. 2. The integral of the function f(x) from a to b is equal to the area under the curve f(x).
   函数f(x)从a到b的积分等于曲线f(x)下面积。
6. 3. The integral of the function g(x) over the interval [-1, 1] is 0.
   函数g(x)在区间[-1, 1]上的积分是0。
7. 1. The derivative of the function f(x) = x^2 is 6.
   函数f(x) = x^2的导数是6。
8. 2.The derivative of the function g(x) = x^3 - 2x^2 + c is 3x - 2.
   函数g(x) = x^3 - 2x^2 + c的导数是3x - 2。
9. 3. The derivative of the function h(x) = x^4 - 2x^3 + c is 6x^2 - 8x + c.
   函数h(x) = x^4 - 2x^3 + c的导数是6x^2 - 8x + c。