I don't know how to reverse cosine decimals into angles. Can you please explain and help me solve these .
cos A= 0.28571428571
A=
cos B= 0.66666666667
B=
cos C= 0.5238089523
If you use a calculator, it would be the cos-1 key.
Depending on the calculator, you would enter the cos value (e.g. 0.2857142857) and press the cos-1 key. Some calculators require the cos-1 key to be pressed first followed by the value.
If you do not use a calculator, let me know what you use, a table of cosines, or something else.
For example, cos-1A is 81.7867893°.
To find the angle given the cosine value, you need to use the inverse cosine function, also known as the arccosine function. The inverse cosine function "cos⁻¹" or "arccos" is the opposite of cosine. It allows you to find the angle (in radians or degrees) whose cosine is a given value.
To solve the equations you provided, you can use either a scientific calculator or mathematical software that has the arc cosine function. Here are the steps:
1. Start by identifying the given cosine value.
2. Use the inverse cosine function (cos⁻¹ or arccos) to find the angle.
Now, let's solve the equations you provided:
1. For cos A = 0.28571428571:
Using a calculator or mathematical software, compute the inverse cosine of 0.28571428571 using the arccos function. The result will give you the angle A in radians or degrees.
2. For cos B = 0.66666666667:
Again, use a calculator or mathematical software to find the inverse cosine of 0.66666666667. This will give you the angle B.
3. For cos C = 0.5238089523:
Similarly, compute the inverse cosine of 0.5238089523 using the arccos function.
Make sure to use the appropriate trigonometric function in your calculator or software when finding the inverse cosine.
Note: The angle values obtained will depend on whether your calculator or software is set to use radians or degrees.