Students In China: Solve A Math Problem For Internet Access!


A calculus problem went viral! Some major websites are reporting that students at a university in China had to solve this for the WiFi password in a dining hall. This is actually a pretty fun calculus problem. Watch the video for its solution!


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  1. If you understand the concept of definite integral and the wrapping function you'll easily get the answer, 3.141592653589793238

  2. I am a post graduate in China,I can tell you guys the first question is a basic calculation in the postgraduate entrance exam.

  3. Then… YOU CAN USE A REFERENCE BOOK THAT HAS A TABLE OF 438 TYPES OF FORMULAS it is what I did then use the Taylor and Maclaurin Theorem to find the sine and cosine values assuming it is is radians as it is an astronomic university

  4. Before watching video:
    When you do enough calculus problems like this and notice that the bounds are additive inverses, then the first thing you look for is an odd function. Always. Once simplified, you can see you have an integral that gives 1/4 area of a circle of radius 2 = π ≈ 3.1415926. Fortunately, it asks only for first 8 digits, because that's as much as I know off the top of my head.

  5. Hi there I paused video tried solving it and did get the answer but ur method of considering equation of circle was just genius (best shortcut to the sum….. )

  6. kindly prove the first part to be zero please by odd symmetry of integration please.


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