I. Entering the Function in the Graph Window

B. Trigonometric Functions

A TI-86 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.


B. Trigonometric Functions