Re: arcsin(arccos(arctan(tan(cos(sin(9))))))

Phil Carmody wrote:
I think a more useful result would be:
arcsin(arccos(arctan(tan(cos(sin(9))))))-9

xcalc gives the answer 9 exactly to the display, but
upon subtracting 9, you see that it's hidden a shortfall
of 3.22746e-11. I presume that other calculators that
display exactly 9 are also hiding a non-zero error.

My Casio fx-115 scientific calculator gives an error
of 1.57179e-05 (in degrees mode). Using 0.4247796
[actually, arcsin(sin(9))] in radians mode gives an
error of -1e-10.

For arcsin(arccos(arctan(tan(cos(sin(1)))))), it gives
an error of 2.028901e-04 in degrees mode, and an
error of 0 in radians mode.

.