Some things to note
The range of each of these three inverse trig functions is different. Each includes the first quadrant and a neighboring quadrant.
arcsin𝑥      Range: −𝜋2,𝜋2 
arctan𝑥      Range: −𝜋2,𝜋2
arccos𝑥      Range: 0,𝜋
Sometimes arcsin𝑥 is written as sin−1𝑥 
Sometimes arctan𝑥 is written as tan−1𝑥 
Sometimes arccos𝑥 is written as cos−1𝑥 
Trig functions turn angles into ratios. Inverse trig functions turn ratios back into angles.