I have a question regarding on how to graph and prove that csc ^2(theta)-cot ^2(theta)=1 our professor provided us with a very poor example, i have to graph the left side of the equation first with a 0 to 2*Pi x-axis and then graph the right side on the same plot. 

I have to generate F(x) of a function with a degree of 5 who has zeros of x=2,x=1+3i,x=2-4i

After i put it into maple i use the command expand to give me the total function but afterwards i get this 144*i^4*x-25*i^2*x^3+x^5-288*i^4+118*i^2*x^2-8*x^4-188*i^2*x+25*x^3+104*i^2-38*x^2+28*x-8

i need to know what command can i use to get it to converts i^4 to 1 and i^2 to-1 that way i can truly simplify it.