The derivation of differential formula assumes that the function y = f(x) is defined in a certain interval, and both x0 and x0+△x are in this interval. If the increment of the function Δ y = f (x0+△ x)? F(x0) can be expressed as Δ y = a Δ x+o (Δ x), where a is a constant independent of Δ x and o (Δ x) is an infinitesimal higher order of Δ x, then the function y = f o(δx) is differentiable at point x0.

The methods of learning calculus are:

1, preview before class

The old-fashioned topic is also inevitable in learning methods. It's an old saying, but I still want to mention it. Although everyone knows what to do, few people can really preview before class. Preview before class can let us know what we want to learn in advance, so as not to be at a loss in class, deepen our understanding during class, and thus quickly absorb new knowledge.

Step 2 take notes

Here mainly refers to the class notes, because the time of each class is limited, so the teacher will usually take the essence, so it is necessary to record it, so as to deepen our understanding and facilitate our review in the future.

Step 3 listen carefully

For college students, especially freshmen, the learning style is very different from that of high school. Teachers usually use PPT in class, but don't think you don't need to listen in class. Just copy the teacher's PPT and learn it after class. Teachers will infiltrate a lot of content that is not on PPT in class. If you miss it, you won't find it on PPT.

Step 4 review after class

Just like preview, it is a cliche topic, but it is also an effective method. A few minutes in class is not enough for us to learn and digest what we have learned. We need a lot of practice and consolidation after class to really master what we have learned.