To find the measure of an angle in a right triangle using a graphing calculator such as the TI-84, you can use the inverse trigonometric functions. Here's how:
1. First, identify the given trigonometric function (cosine, sine, or tangent) and the corresponding ratio.
- In your example, the given trigonometric function is cosine (cos A = 0.7986).
2. Press the appropriate inverse trigonometric function on your calculator.
- For cosine, press the "cos^(-1)" or "2nd" followed by "cos" key.
3. Enter the value of the given trigonometric function.
- In your example, enter 0.7986.
4. Press the "=" or "Enter" key to calculate the inverse cosine.
5. The calculator should display the measure of the angle in radians.
- If you want the answer in degrees, you can convert it by pressing the "2nd" key followed by the "Angle" key (which looks like "°") on your calculator.
So, by following these steps with the given information of cos A = 0.7986, you should be able to find the measure of angle A using a TI-84 graphing calculator.