Exponential functions - where to begin?

Consider an exponential expression, like f(x) = A(1.5)^x. I read the question and then look at two values of x that usually shorten the solution.

1. x = 0 makes f(0) = A(1.5)^0. (1.5^0 = 1, so f(0) = A, which is the initial value of the expression.

2. x = 1 because that shows how the expression changed in an interval of 1. Exponential expressions are often interest or depreciation calculations, and if you compare the values at x = 0 and x = 1 it tells you what happened in the first period. That will often show you right away which of the multiple choice answers makes no sense!