After that, no one mentioned the stubble of the previous speech contest, because it was exam week in the blink of an eye. Pen & Fun & Pavilion www.biquge.info Whether you are the president of the student union or the unknown otaku rotten girl, everyone is equal in front of the exam, which makes my heart feel a lot better. Because finally I can compete with them on the same starting line.

I'm good for nothing else, and I have low self-esteem, but in my studies, I will never lose to others.

The school, which is close to the depths of winter, is slowly wrapped in a layer of plausible haze, caressing the mist, as if in a fairyland on earth.

I picked up last year's exam paper for Advanced Mathematics and was silently alone in the library's study room, looking for damn limits and differential equations. The general solutions of those higher-order linear nonhomogeneous differential equations inevitably made me a little anxious, and the answer given by the teacher was a little worse. I got up slightly and walked to the door of the library, taking advantage of the cold winter wind to try to keep me awake and change my thinking.

When I got back, I found that my scroll had obvious traces of being moved, and I didn't care, because it was normal for my books to have been passive in this place where people were too busy and unruly.

When I sat down, I was still worried that I hadn't solved the higher-order linear nonhomogeneous differential equations that I had just solved.

At this time, a girl next to me tentatively patted my arm, and I turned my head to find a girl with a flushed face, all her hair combed back, and a clear hairline on her forehead, looking straight at me.

My face turned red in an instant. Missing the gap between her eyes, I couldn't help but look elsewhere.

She asked me tentatively: "Classmate, how do you calculate the volume of a round table on top of the hemispherical surface of this triple integral?"

I looked where he was pointing and saw a very strange three-dimensional geometry.

I thought about it and said: Actually, this one is relatively simple. You don't have to use the triple integral to solve, the following hemisphere you can directly according to the equation given by the triple integral, see its radius, and then set the formula to find, the upper part of the circle, we can use the triple integral to solve, divided into three steps, the first step is to see the expression of the polar coordinates of the circle table x=ρcosα, y=ρsinα, z=z, the second step, you take its polar diameter ρ as the product object, the line integral products a small trapezoid, and the area division is based on the online integration of the surrounding 360 degrees, and the small round platform is accumulated. The volume integral is based on the area fraction and the height integral to accumulate the large round table. Finally, just add the semicircle just now.

The girl nodded thoughtfully, and kept looking at the question without moving. I seemed to see her anxiety, so I wrote down the complete process of solving the problem on scratch paper and handed it to her, and he took my scratch paper and went to study it alone.

And I, still thinking about the general solution of my higher-order linear nonhomogeneous differential equations.

In my judgment, he either sent a sub-question or a proposition. Obviously, he is a proposition.

It didn't take long for my arm to wake up again.

The girl, tentatively and cautiously, said: That...... Classmate, this triple integral is too difficult. I still don't understand, can you make it easier to understand?

It's a pity that the new idea I had just come up with was ruined for such no reason. I didn't have a seizure.

Then, I will start with the reason for the triple integral, first of all, everything is composed of an infinite number of points, this point is the element of our integrand, and the ordinary one-time integration is the addition of countless elements in a limited range in one-dimensional space to form a line. The double integral is extended to the two-dimensional space on the basis of the one-fold integral, at this time his micro-element becomes a micro-line, and the countless micro-lines are added within the range of the product to obtain a surface, and the triple integral continues to be extrapolated and extended into the three-dimensional space, and the micro-element becomes the micro-surface formed in the double integral, and the countless faces are added within the range of the product to become a body. So, the first integral is the length, the second integral is the area, and the third integral is the volume.