Recent content by stevekho

Also I know how to prove it but could you give me a better f(x)

(If you have a nicer f(x) could I also have a hint?)

"Suppose a is a real number. Then a2>|a| if |a|>1 but a2<|a| if |a|<1." ... sin(1/x)/x is integrable in R I saw (sin(1/x)/x)^2 is not integrable in R Could someone confirm me?

So you think I should multiply and then if I find for instance That row1col1 goes to + inf and row2col1 goes to -inf then there is no limit?

Basically I should only work my my diagonal matrix B? But how can we estimate the limit of a matrix? For instance, if c<3, 3^n/c^n will go to infinity when n goes to inf (like 6 and 9) For 6>c>3 (3/c)^n goes to 0 (6/c)^n goes to inf (9/c)^n goes to inf How from that I can find a...

Well in that case, we are in R so f^2 will be positive so could be too big as x goes to inf. :/

Give an example of a function f : R -> R, such that f is integrable but f^2 is not integrable. Prove your result. Seriously I don't know where to start, please help me guys

Hello, Do you have any idea where I could find my formula for the Grashof N°, Nu and Heat? Thank you very much for your help Steve

Ooooooook I found it :)

Hello, I have an electric cable in a vertical steel Tube. I estimated the temperature that will reach the JTube exposed to sun radiation. I came with these equations QCable+ Qsun - Qradiated = mc( Tfinal - TAmbient) where QRadiated= k.A.(Tfinal^4-TAmbient^4), QSun=234 [W/m^2] * A...