Casio fx-991EX Classwiz Review

[lrdheat]

History is gone when powered off...variables stored in memories remain. Wish I could define f(X) in table, and use it in calculate mode to solve for roots or solve d f(X)/dx to find max/mins without having to retype the function in. Wish I could do the reverse process as well. That said, solve is great. I can do solve d/dx, then delete the d/dx and hit = to get the f(X) value for where d/dx = 0. I can even solve integral from point of interest to X to find what X value results in the integral producing some assigned value.

Solve and integral returns values accurate often to full display where as TI 36 Pro often is accurate to about 5 digits.

Polynomials return all zeroes including imaginaries, degree 2 returns zeroes, and the X and y values of the polynomial's max or min.

In regression, one can store a,b,c constants that the regression calculation generates, and use in rewriting the equation in calculation mode, and find predicted y value for given X or predicted X value for given y.

A nice pocket companion.