Casio fx-991EX Classwiz Review

[lrdheat]

On the 991EX, I can type in an equation such as d/dx(sin(x))=0 ,enter the solver, put in a guess such as 2, and it will report a number equivalent to pi/2. It even works in the solver if I simply enter d/dx(sin(x)) It assumes in this case that I want to find a root.