Posted by **Anon** on Sunday, February 27, 2011 at 6:53am.

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 -
**MathMate**, Sunday, February 27, 2011 at 8:43am
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^{-1}A is 81.7867893°.

## Answer this Question

## Related Questions

- Trig. Law of Cosines - Show that any triangle with standard labeling... a^2+b^2+...
- tigonometry - expres the following as sums and differences of sines or cosines ...
- trig - Reduce the following to the sine or cosine of one angle: (i) sin145*cos75...
- Math - Eliminate the parameter and write the corresponding rectangular equation ...
- Trigonometry - There is an arbitrary triangle with angles A, B, and C and sides ...
- MATH...THE GRAPHS OF SINE, COSINE AND TANGENT - anyone explain how this cos 2A ...
- Spherical Trigonometery - I am trying to apply the formula cos c = cos a x cos b...
- calculus - pleaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaasw help can you pleaaaaase ...
- calculus - Differentiate. y= (cos x)^x u= cos x du= -sin x dx ln y = ln(cos x)^x...
- Calc. - Differentiate. y= (cos x)^x u= cos x du= -sin x dx ln y = ln(cos x)^x ln...