I think what would help you here is the command getKey. It returns the last key pressed as a number based roughly on what row and column it's on on the keyboard (and 0 if nothing). For instance, the sin( key is in the 5th row and 2nd column, so you would check in this instance if getKey = 52. (In practice, you're almost always gonna want to store this to a variable and instead check that.)
The arrow keys are a bit more complicated. Up, left, and right are considered in the second row, and down is considered in the third row. So left is 24, up is 25, right is 26, and down is 34.
Also, any particular reason you have a While 5=5 loop?