## hkmiu one year ago cos(arctan(sqrt3/7))?? http://media.education2020.com/evresources/649-07-06-00-00_files/i0200000.jpg

1. hkmiu

$\cos(\arctan (\frac{ \sqrt{3} }{ 7 }))$

2. myininaya

Let the inside be called a. arctan(sqrt(3)/7)=a then use the fact that tan is the inverse of arctan to rewrite that as tan(a)=sqrt(3)/7 Draw a right triangle and put these measurements in their proper place. You should see that one measurement for one leg is missing. You can use the Pythagorean thm for that. Then find cos(a) and that is your answer.

3. hkmiu

Oh okay, thank you !!! :D

4. myininaya

Ok. Well if you have anymore questions here on this problem don't be afraid to ask.