What is the purpose of a function? Say i want to find the revenue of a company for a given product sold. R = n(p). 1.0 = 2(.50). Now express R as a function of n. R(n) = 2n(0.50n), R(2) = 22(0.502), R(2) = 4(0.25).

But what's with the R(2) = 4(0.25) part?