Cubic and Quartic Formulae

[LCieParagon]

(08-07-2015 10:39 AM)Manolo Sobrino Wrote:  Did you really try that or it's just guessing? It's a dead end...

If you solve: sin(3x) = 3sin(x) - 4sin^3(x) by letting x = 1, you can find the value of sin(1) which you listed above. Like I said, Maple computes this value flawlessly. I don't see why a calculator can't do the same. This calculator has more than the capabilities of doing so.

I've also noticed approximations with certain products and sums that one can derive from using residues from complex analysis.

For instance,

Our HP Prime has no ability to compute such things. I use residues frequently in my graduate studies.