Inaccurate results for trigonometric functions with exact results

Describe the bug The below examples of the trigonometric functions show a correct result at first. However, subtracting that result from itself results in a non-zero value, which shows that the results are represented as incorrect approximations internally, when it should be an exact result.

In DEG mode: arcsin(1) - 90 != 0 sin(30) - 0.5 != 0 In RAD mode: sin(π/2) - 1 != 0 but interestingly: cos(±π) + 1 == 0

This is a new issue spawned from the similar issue #222.

Steps To Reproduce

1. Try the above calculations in scientific mode

Expected behavior Exact internal representation and result 0 for above calculations.

Device and Application Information (please complete the following information):

• OS Build: 10 0 17763 0
• Architecture: X64
• Application Version: 10.1812.10048.0