After a few minutes, the water pipe was unblocked. The professor was quite satisfied with the plumber's performance, but when he saw the bill, he couldn't help shouting, "Wow!
t！ In just 30 minutes, the money you collected is enough for my monthly income 1/3! I want to be a plumber! "。 The plumber said, "What's the matter?"
You can go now. Our company is recruiting people, including training. But you have to say that you just graduated from primary school. The company doesn't like it
People with too high academic qualifications. "So the professor went to the training and became a plumber. His income tripled at once. Tabby
I was much happier before. A few years later, the company suddenly decided to raise the educational level of plumbers to junior high school graduation, and then asked
All its workers go to night school. The first class at night school is math. The teacher wants to see the basic situation of these plumbers first.
How nice, so he randomly chose a person to write the formula of circular area. The professor was painted, but he did.
As a plumber for many years, he has forgotten that the formula of circular area is π * r 2. So he has to deduce from the beginning: infinite cycle.
Integral after division. But the result he got was negative π * r 2. Embarrassed ing, the professor never came again, and the result was still negative.
. Embarrassed, he turned to dozens of plumbers sitting in the classroom for help. I see that these colleagues are all
They whispered to him: the upper and lower limits of exchange integral.