When using scientific calculators for tests, memorize the locations of keys such as the arcsin beforehand. Doing so will allow you to confidently work equations and be more efficient on time-sensitive tests.
Acrsine represents this equation: if y is the sine of θ, then θ is the arcsine of y. The arcsine is the inverse of the sine function.
To calculate arcsin, press the "2nd" button and then the "sin" button. This will produce the "sin^-1" button. Enter the value you wish to calculate and press enter. The answer will appear.
For example, calculate the arcsin of 3. First, press "2nd." Next, press "sin," and "sin^-1" will appear. Then press 3, and the equation will appear as sin^-1(3). Press "Enter" to calculate the answer.