Education Technology

# Knowledge Base

## Solution 10348: Calculating Inverse Trigonometric Functions on the TI-85 or TI-86 Graphing Calculators.

### How do I calculate inverse trigonometric functions on the TI-85 or TI-86 graphing calculators?

Most inverse trigonometric functions are calculated in angle measurements of degrees. The steps outlined below will change the mode from the default setting of radians to degrees for the measurement of angles. However, if this step is omitted the measure of the angle may be in radians and not degrees.

• Press [2nd] [MODE] • Highlight Degree then press the [ENTER] key.• Press the [EXIT] key to return to the home screen.

The examples below will demonstrate how to input inverse trigonometric functions using the TI-85 or the TI-86 graphing calculators:

Example #1Find the Inverse sine of .5 • Press the [2nd] key and then press the [SIN] key• Input [(] .5 [)] and press [ENTER]

The screen will show 30.

Example # 2Inverse cosine of .5 • Press the [2nd] key and then the [COS] key• Input [(] .5 [)] and press [ENTER]

The screen will show 60.


Example #3Inverse tangent of .5 • Press the [2nd] key and then the [TAN] key• Input [(] .5 [)] and press [ENTER]

The screen will show 26.56505...

Please see the TI-85 and TI-86 guidebooks for additional information.