Trigonometry

There are a couple of important things to remember when doing trigonometry on your calculator.

Radians or Degrees?

Be sure that you go to <MODE> and choose whichever of radians or degrees you are using for the particular problem

Parentheses

Often you will see things like cos²x.  That is mathematical shorthand for (cos x)².  On your calculator, it will need to be entered as in the window shown to the right.

Reciprocals of Trigonometric Functions

You will occasionally want to use secant, cosecant or cotangent.  Though they are the reciprocals of cosine, secant and tangent respectively, they are NOT obtained by using the keypad functions cos^-1, sin^-1, or tan^-1.  On the TI-89/92, in order to enter them, use either of the formats shown below.

If you are using the Voyage 200 these functions are built in.  In order to enter them, go to "MATH" "TRIG."