Question

Do you think WolframAlpha gave the correct acute angle approximation for the equation?

Answer 1

Here it is:

Answer 2

URL: http://www.wolframalpha.com/input/?i=cos%28x+degrees%29+%3D+5%2F13

Answer 3

My calculator cranked out 67.380 degrees approx

Answer 4

it is the same; if you set n to be zero in the approximation form

Answer 5

@RED123url I don't understand what you are saying.

Look at this.