Issues with integral

[trojdor]

(08-19-2020 09:03 PM)Mordicus1973 Wrote:  Hello,

i try to compute this integral
int(1/(sqrt(cos(x))+sqrt(sin(x)))^4,x,0,pi/2)

The calculator simply hang, i can't stop computing. in the emulator it show some messages and don't do the computation.

When i do the same computation on Nspire or wolfram, i have to right answer (1/3).

I have tested with xcas on Linux (icas), it can't compute this integral.

Interestingly...
It works perfectly fine if you enter the integral in Home mode...gives you an instantaneous .333333333... or 1/3.

It's usually the other way round for me .... CAS will frequently solve things Home won't.

I was bored and tried this problem on about 20 calculators I had within arm's reach. Every one got it right. Even the old HP-48 eats it right up.
The TI-89 CAS got it right. Same with the HP50g, 40gs, 49g, some Casios.