First, simplify the radicals
√125=√(5*5*5)=(√5*5)(√5)=5√5
so 3√125=3*5√5=15√5
and √16=4
so
15√(5)-4 is the simplified version
Basically, you are looking for the ARC SINE of .994 which is
83.72 Degrees
You could also use an online calculator:
http://www.1728.org/trigcalc.htm
