Question: what is the difference between sinx and sin-1(x)?
Answer: Intuition states that 1/sin(x) is the same thing as sin -1 (x), just like 2 -1 is the same thing as 1/2. In case you're not familiar with arcsin, it's sort of the reverse operator of sine. You put a ratio of 2 lengths in, and you get an angle out. Same thing for arccos and arctan.