Texas Instruments TI-89 Tip List page 421

nsolve(sin(2x)=cos(x),x) returns -10.9956 (radian/ auto mode)
nsolve(sin(2x)=cos(x),x) | x>=0 and x<2Pi returns 4.71239 (radian/auto mode)
Store a value to a matrix element.
If mat1 is a 3x3 matrix, then 12->mat1[2,3] will store the value of 12 in the 2nd row, 3rd column
position. The TI-8x products used parenthesis instead of square brackets to do this. Parenthesis on
the TI-92 are reserved for function and program calls.
nDeriv() (numeric derivative) algorithm.
nDerive(f(x),x,h) => (f(x+h)-f(x-h))/(2h)
Calculator will not accept a key press - why?
A key may be stuck down, putting it in the active position. This blocks any other key from being
accepted and your TI-92 may appear to be locked up. Unstick the key and you should be ready to
operate.
Can I use the link port for my own applications?
No, the link port was designed to optimize our communications speed and the protocal is not general
enough for other applications.
Adding features to the existing TI-92.
Through the use of programs, user-defined functions, and geometry macros, you can add functionality
to the TI-92. User written programs and functions can be downloaded from the program archive
You can also upgrade your TI-92 with the TI-92 Plus Module with Advanced Mathematics Software.
Anti-derivatives - why can't the TI-92 find them for all expressions?
Finding anti-derivatives can be very difficult, requiring more program ROM than is available. Moreover,
it is theoretically impossible to express all anti-derivatives as a finite composition of the functions and
operators built-into the TI-92. However, the TI-92 will find anti-derivatives for most integrands
encountered in most calculus texts and in tables such the the CRC handbook.
There is a function nInt() for finding numerical values of definite integrals where anti-derivatives can not
be found using the symbolic techniques. In Auto mode, numerical techniques are used automatically
when needed for definite integrals.
Can't see displays because of the classroom lighting.
Try adjusting the display contrast using [diamond] [+] to darken the display or [diamond] [-] to lighten
the display. Also try using the cover as a stand to improve your viewing angle.
arcLen() (arc length) function algorithm.
The implemented textbook definition arclen (u,x,a,b) = integral (sqrt (1 + d(u,x)^2), x, a, b) is actually a
more useful arc-DISPLACEMENT: The integrand is positive for real u.
If the lower limit exceeds the upper limit, then dx is negative, making the result negative.
Cabri Geometry II features not in the TI-92.
Conics, circle filling, multiple animation, and construction replay. Also some computer specific
functions (like color selections and cut/copy/paste) have been removed.
Cabri II is not built in the TI-92. Texas Instruments worked with the authors of Cabri Geometry II to
jointly develop a geometry package for the TI-92. Many of the features of Cabri II are in the TI-92.
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