If given an a cos, sin, or tan of an angle of a right triangle, what steps would you take on your calculator to find the measure of that angle? (For example: cos A = .7986, find angle A, The opposite side is 3. The hypotnuse is 5. And the adjacent side is 4)
If someone would just explain what to do with a graphing calculator (TI-84), that would mean a lot! thanks
You write:
"For example: cos A = .7986, find angle A, The opposite side is 3. The hypotenuse is 5. And the adjacent side is 4"
but for a 3:4:5 triangle, the cosine is 0.8.
I don't have your calculator, but what you need is a cos^-1 or arc cosine key.
If cosA = 0.7986, A = cos^-1 0.7986 = 37.003 degrees.
To find the measure of an angle in a right triangle using a graphing calculator (TI-84) when given a value of cosine (cos), sine (sin), or tangent (tan), you can follow these steps:
1. Go to the "MODE" menu by pressing the "MODE" key on your calculator.
2. Make sure you are in "Degree" mode by scrolling down and selecting "3: Degree" using the arrow keys.
3. Press the "2nd" key (yellow key) followed by the "MODE" key to exit the "MODE" menu.
Now, let's consider an example:
Given:
cos A = 0.7986
To find the measure of angle A, you can follow these steps:
1. Press the "2nd" key (yellow key) followed by the "COS" key ("ALPHA" key followed by "COS") to access the inverse cosine or arccosine function on your calculator.
2. Enter the value of cos A (0.7986 in this case).
3. Press the "ENTER" key.
4. The calculator will display the value of the angle in degrees. Round this value to the nearest degree or decimal place as necessary.
In the given example, performing the steps above would yield the measure of angle A.
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.