TI Hints

Andy Long

  1. Use solve to find a solution to an equation: e.g.

    displaymath155

  2. Use expand to expand out a function: e.g.

    displaymath156

    or

    displaymath157

    (expands in terms of x by default). If you want the expansion in terms of a, then you would type

    displaymath158

    which would give

    displaymath159

    Note:

    displaymath160

    displaymath161

    displaymath157

    The coefficients of each term come from Pascal's triangle:

    displaymath163

    Etc.!

  3. TI hint: Use factor to factor an expression: e.g.

    displaymath164

    Factor will try to create linear terms in x (by default), i.e.

    displaymath165

  4. To differentiate an expression, use the d command (from the calc menu): e.g.

    displaymath166

    returns tex2html_wrap_inline199 . I personally prefer to define a function in the ``Y='' menu, e.g.

    displaymath167

    and then use

    displaymath168

    If you have to use a function over and over, it's usually smart to define it in a way that will be stored for future use.

    Now we can do things like solve for where the derivative is zero:

    displaymath169

  5. The tExpand command (available from the Algebra -> trig menu) is useful for expanding out trigonometric expressions:

    displaymath170

    for example yields tex2html_wrap_inline201 , one of the most important trig identities.

    displaymath171

    yields another: tex2html_wrap_inline203 .

  6. To make a sum, use the tex2html_wrap_inline205 key (2nd-4 on a TI-92; F3-4 on a TI-89). As usual I do this in ``Y='' menu, e.g.

    displaymath172

    This command would represent the sum

    displaymath173

    which is similar to the type of sum we need when creating Riemann sums.





LONG ANDREW E
Tue Mar 27 20:30:41 EST 2001