trig
posted by dolora .
how do you solve 2nd cos 6/11 (my calculator doesn't have 2nd function0

some calculators have a key called "INV"
try
INV
COS
(6/11)
=
You should get appr. 56.944
If you have a key called "cos" , then at that keyt on the body of your calculator you should see cos^1
in that case your calculator is able to take the inversecosine, sometimes called arccosine. 
found it, thanks!