Finding Roots of Derivatives on Casios

[klesl]

For 115/991: excerpt from UG
Important!
If an equation contains input functions that include an open parenthesis (such as sin and log), do not omit the closing parenthesis.
The following functions are not allowed inside of an equation: ∫, d/dx, Σ, Pol, Rec.
https://support.casio.com/global/en/calc...SOLVE.html

For 991EX (ClassWiz)
d/dx(3x^3-10x^2+15) /x=A=0; solve for A, the 2nd equation sign next to the 0 is red on the keyboard (alpha+calc)
press shift+calc (solve)
scroll down to see A (not X) and enter value
press enter to get the root x=2.2222222222 or 20/9 and x=0