Bad day.. but not so bad

It started when I checked my NUS email.. I had previously emailed to my "Mathematical Methods in Physics" lecturer to ask him about some stuff that I didn't understand in the textbook.

Here's the original email I sent him.

Dear Sir,



1. With reference to Mary L Boas' textbook page 308 equation 5.3, why is the integral of sinmx = [expimx - exp (-imx)] / 2i ??



2. Why is exp ikπ = exp -(ikπ) = coskπ ?



Generally a little confused about expression of sine and cosine terms into complex exponential form. Please advise! Thank you!



TS

Here's his reply..

I think you forgot almost everything you learned in high school (or JC).



sin(x)=(exp(ix)-exp(-ix))/2i



cos (x) =(exp(ix)+exp(-ix))/2



and

exp(ix) = cos(x) + isin(x)



These are called Euler formula.



If you have difficult in this formula, you should work harder. These are very elementary things.



******

I mean, thanks dude I so needed that reminder you fucking piece of smartass trash. And wow, you basically re-typed everything I asked you about. No wonder you told the class that the 打包 rate for this module is high. Of course man, with you around who needs teachers? Whatever mood I had for the day, he totally crushed it. Fucking asshole, so smart then GO HOME LAH... why come here and use our taxpayers money and do your stupid pointless half-million research so that soldiers can be cooler during wartime? Retard..

Thought of gathering the Buangsters for supper so I msg-ed all of them and initially the response was good. Then I totally forgot Hardcore was coming over to my place to get some mp3s from me so that's strike 1.
Strike 2, I didn't msg J the time so yeah she kind of waited for quite long with her friends.
Strike 3, I had to use my mother's phone to msg J and other Buangsters, conjuring a huge mother-of-all-messes...

I swear this is the last time I'm organising supper.