Fsinx is approximately 0.2588, what is the measurement of x to the nearest degree? approximately, what is the cosine of the angle that is complementary to x?

There are buttons on all scientific calculators for inverse trig functions.

Usually denoted as "arcsin, arccos" or with a little -1 inverse sign like this:
 

You put in the measurement and it gives back the angle. I

angle x = 15°

complimentary angles add up to 90° so the angle that's complimentary is 90-15 = 75°

Add them all together then u will get your answer

Haidbysksusnsjshusjh