Graphing Calculator Tips

for TI-85

The calculator you use must have four built-in capabilities:


Graph a function

 

     (1) Press <GRAPH>

      (2) Press <F 1> to enter function for y(x)=

 

     (3) After entering function, press <EXIT>

     (4) Press <F 3> to Zoom

              (a)  Press <F 4> for Zoom Standard (10x10)   or

              (b)  Press <More> then <F 3> for Zoom Trig

 

     (5) Press <EXIT> then <F 5> for graph.

     (6) Press <F 4> for Trace, then use arrow keys to trace curve.

 

     (7) Press <F 2> for Range to set up your own domain and range.

     (8) Press <MORE> twice then press <F 1> to Evaluate the function at a particular x.

 


 

Solve an Equation

 

     (1) Press <2nd> <SOLVER>

     (2) After the Eqn: You should enter your equation – you must press <ALPHA>

          <STO> for the = sign.

 

     (3) Press <ENTER> to get the Interactive Solver Editor

     (4) Make a guess for x =

 

     (5) You may change the bounds (the default bounds are {-1E99, 1E99}).

     (6) Press <F 5> to solve equation.   

 

     (7) Repeat with different bounds to solve for other roots. 

           Use this in connection with the Graph capability to see where other roots may be.

 


 

Calculate a Numerical Derivative

     (1) Press <2nd> <CALC>

     (2) Press <F 3> for the first derivative.

 

     (3) After der1(  is displayed,

             enter your function,

             then a comma,

             then the variable x,

             then a comma,

             then the value at which  you wish to take the derivative,

             then a right parenthesis.

     (4) Then Press <ENTER> to get the numerical value of the derivative.   

 


 

Calculate a Definite Integral

     (1) Press <2nd> <CALC>

     (2) Press <F 5> for the integral.

 

     (3) After fnInt(  is displayed,

             enter your function,

             then a comma,

             then the variable x,

             then a comma,

             then the lower bounds of the integral,

             then a comma,

             then the upper bounds of the integral,

             then a right parenthesis.

     (4) Then Press <ENTER> to get the numerical value of the integral.