Question

Which is equivalent to `sin^-1(0.75)` and how do you round your answer to the nearest hundredth of a radian?

Answer 1

`0.85; 2.29` radians

Explanation:

`sin^-1 (0.75) --> arcsin (0.75)`
Calculator gives
sin x = 0.75 --> arc `x = 48^@59`
Trig unit circle gives another arc x that has the same sin value (0.75):
`x = 180 - 48.59 = 131^@41`
Convert to radians:
`48^@59 --> (3.14/180)(48.59) = 0.85` radians
`131^@41 --> (3.14/180)(131.41) = 2.29` radians.