I. Entering the Function in the Graph Window
B. Trigonometric Functions
A TI86 has keys for three trigonometric functions: sine, cosine, and tangent. You will have to use a ratio to graph cosecant, secant, and cotangent.
1. Entering Sine, Cosine, Tangent
You will need to use parentheses when entering most trigonometric functions.
Example: Enter the functions shown below.

Enter a simple trig function.

Close the parentheses.


The
key is
.


You cannot enter this as it
is written.


You need parentheses
around the fraction. 

Functions entered. 
2. Entering Cosecant, Secant, Cotangent
These functions will require the use of the reciprocal identities.
Example: Enter the following functions.
Put parentheses around the 2x.  
The coefficient is
not put in the denominator. 

There are several
ways that this function could be entered, but until you have experience entering functions, just use the keystrokes shown in the window below. 

Functions entered. 