Second Derivative Description
to view the calculus menu, then
to select the second derivative option, der2.
The syntax is:
The second derivative option algebraically finds the second derivative
of expression with respect to variable at value.
If value is omitted, the current value of variable is used.
Note: Unfortunately, the TI cannot differentiate some functions
algebraically. For these functions use the less accurate
numerical differentiation option nDer twice.