cosines

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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

  • cosines -

    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°.

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