It burns through just about everything, except teflon, right? Can you describe the extra laboratory precautions that you had to take when handling that stuff ? And (if you are at liberty to) what you used it for ?
In regards to post #9:- I'm not entirely sure what you're trying to do here. Did you have a look at the links I provided in post #8. I think your trying to come up with a value for ##\int_0^{\pi} \frac{1}{1+\alpha cos(x)} dx## for ##|\alpha|<1##using ##\int_0^{\pi} \frac{1}{\alpha-cos(x)}...
See this, example 3.
Now let's do that daunting looking integral. Like I said before, this is a good problem.
First write ##\int_0^{\pi} \frac{1}{\alpha}-\frac{1}{(\alpha)(1+\alpha cos(x))} dx## for the original integral.
However ##\int \frac{1}{1+\alpha cos(x)} dx## itself is not nice, in-fact...
Hmmmm...I see your point of view.
[Edit:- I am, more or less self taught. So sometimes there exist these small gaps in my knowledge, that make me look like a complete beginner :-)]
But there are also the floor and ceiling functions which have constant 2nd derivatives, where they are continuous and also the sawtooth function (the fractional part of ##x##) which will have a constant 2nd derivative when ##x## is not an integer.
But analytically speaking aren't we first taking the absolute value and then squaring it, so it shouldn't be a polynomial right ? (I wasn't sure of this, that is why I said "I think")
There is a good deal of material. For instance the corollary to a theorem of Fermat :- "Any prime ##p## of the form ##4k+1## can be represented uniquely as the sum of 2 squares. Or (related) Lagrange's theorem:- "Any positive integer ##n## can be written as the sum of 4 squares, some of which...