# Solution 66: sec(sum(csc(tan(cot(sin(cos(...)))))))

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**Published on Nov 15, 2018**- Let's telescope our way through the odd functions.

Congratulations to Jaleb, Kevin Tong, Hiren Bavaskar, reynolds45, Bigg Barbarian, Rohit Agarwal, Aswini Banerjee, Ricardo Mogollon, Albanovaphi7, and aby p for successfully solving this math challenge question! Jaleb was the first person to solve the question.

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Welcome, everyone! My channel hosts one weekly math challenge question per week (made by either myself, my family, or my friends), which will be posted every Wednesday. Please comment your proposed answer and explanation below! If you are among the first ten people with the correct answer, you will be recognized in the next math challenge video. The solution to this question and new question will be posted next Wednesday.

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Alex Larking9 days agoI love this haha

It's the THUG25 days ago^{+1}Jaleb is illuminati

Sven Cats2 months ago^{+1}Awesome video! This problem looks even a bit nicer in 2019, as you can go from 0 to 2019 and replace the 5 by a 1

Yerram Varun6 months agoBeautifully done!

Nicholas Leclerc6 months ago^{+1}You should reveal the answers of some commenters AFTER the whole video, to avoid spoilers !!!

Nick7 months ago^{+2}Hi, I have a problem for you.

find:

limit of the integral of ((n^c)(e^-((x^2)(n^2)))dx) from 0 to c as n approaches infinity such that c is a constant and c>1.

Does the function inside converges?

Harshit Gupta7 months ago^{+2}good video.....now solve......integral limit( minus one to zero) ((x)^(4)-2x^(2))^(1/3)+√(1-√(x^(3)+1))

柯仲遠7 months ago^{+1}幹 太強了

Facebotter7 months ago^{+2}Do you solve these while making the video or beforehand?

Facebotter7 months ago^{+2}@LetsSolveMathProblems I love the sense of spontaneity! Presupposing the audiences questions and confusions is really cool :)

LetsSolveMathProblems7 months ago^{+5}I always have at least one complete solution prepared for every weekly math challenge question before the problem is posted. In general, I spend around thirty minutes to a few hours of preparation time prior to actually filming a video

Saroj si7 months ago^{+2}nice Sir many many thanks to you

Bessel J7 months agohmmmmmm

Math 12347 months agoPlease can you explain fractional derivatives and fractional integral step by step

Brian talks about7 months ago@Math 1234 come to my channel. It's a little more advanced. But I use fractional derivatives to analyze the zeta function. The 1st and fourth videos use fractional calculus.

Also try to solve my problem in my 5th video!!!! Yay!!!

Brian talks about7 months agoMy channel is gonna do alot of fractional derivatives

Math 12347 months agoNo I mean one half derivatives of any functions ......in general l mean m/n derivatives or integral of any functions

Monster Azice7 months agoMath 1234 you mean partial derivatives and integration by parts?

Moslema Sultana7 months ago^{+1}what the heck! I saw 1 to 2018! 😭😭😭

Linus Schwan7 months ago^{+18}Great video, I always enjoy these cool problems. Just one suggestion: Maybe you could show the first comment with the right answer at the end of the video or just show their name at the start. That way the answer won't get spoiled so early, which in my opinion would make the video more interesting to watch.

Brian talks about7 months agoCome solve my problem now usclip.net/video/B4DGg8KwBYE/video.html

Linus Schwan7 months ago@LetsSolveMathProblems You're very welcome!

LetsSolveMathProblems7 months ago^{+4}That is an excellent suggestion. In the next solution video, I will just reveal the name of the comment at the beginning and see if there are any downsides of doing so. If there are no viewers criticizing the new format (with a well founded reason), I will make the implementation permanent. Thank you so much for your helpful suggestion! =)

SUPRATIM SANTRA7 months ago^{+4}Sir please upload such... Interesting problem more..

Aliasger Anees7 months ago^{+3}Best question to apply even and odd function concept.

Ojas sevekar7 months ago^{+3}Amazing telescopic

DrWaffles7 months ago^{+29}You did all of that to get sec(0). I appreciate the effort

Colin Pountney7 months agoDrWaffles n