Question

What is the value of: sin^-1 0.6349, sec^-1 0.5496, tan^-1 0.3457

Answer 1

The secant of an angle cannot be less than 1. Therefore sec^-1 0.5496 is meaningless.

For the others, use a hand calculator or Google (which will give you the answer in radiansas in this example:
http://www.google.com/search?hl=en&rlz=1G1GGLQ_ENUS357&ie=ISO-8859-1&q=arcsin%280.6349%29&btnG=Search