Legend

Square root of x = sqrt(x)
x squared = x^2
use pi for 3.14!
sin(x)
cos(x)
tan(x)
inverse tangent = arctan(x)
inverse cosine = arccos(x)
inverse sine = arcsin(x)
absolute value of x = abs(x)

To add a function, click on add function and type in the function using the variable x.  Do not type y =!!  You can add as many functions as you need.  Delete function will delete the last function entered.