Thanks Badinage,
I usually do it that way too. But be warned ..... :)
I entered sin(acos( 0.6372))
$$\underset{\,\,\,\,^{\textcolor[rgb]{0.66,0.66,0.66}{360^\circ}}}{{sin}}{\left(\underset{\,\,\,\,^{\textcolor[rgb]{0.66,0.66,0.66}{360^\circ}}}{{cos}}^{\!\!\mathtt{-1}}{\left({\mathtt{0.637\: \!2}}\right)}\right)} = {\mathtt{0.770\: \!698\: \!488\: \!386}}$$
Only thing you need to be careful of is the sign.
Cos is pos in the 1st and 4th quad. Sin is pos in the 1st but neg in the 4th
so
the answer can be + or - 0.7707