Whats the inverse of f(x) = 2arcsinx?

f^-1(x)=
i got sin x/2 but the choices are..

1/2sin(x)
sin(1/2x)
sin(2x)
2sin(x)

Which of the following is correct interpretation of the expression -4+13

Use the distributive law to multiply. 3(4x + 5y + 6)

The first-serve percentage of a tennis player in a match is normally distributed with a standard deviation of 4.3%. if a sample of 15 random matches of the player is taken, the mean first-serve percentage is found to be 26.4%. what is the margin of error of the sample mean? a. 0.086% b. 0.533% c. 1.11% d. 2.22%