Answer: Mark needs to calculate the amount of state tax by multiplying 250,000 by 0.10, and the amount of federal tax by multiplying 250,000 by 0.25. He then can add the two tax amounts.
The range of sin(x) is [-1,1]. No matter what the value of x,pi,pi/2,pi/4,pi/6,-pi/2,etc the value of sinx will always be between -1 and 1(both included)