SOLUTION: How does sec(cos^(-1) 1/2) equal to 2? I know that cos 1/2 is at 60 degrees and 300 degrees, where do I go from there?

Algebra ->  Test -> SOLUTION: How does sec(cos^(-1) 1/2) equal to 2? I know that cos 1/2 is at 60 degrees and 300 degrees, where do I go from there?      Log On


   

Question 432637: How does sec(cos^(-1) 1/2) equal to 2? I know that cos 1/2 is at 60 degrees and 300 degrees, where do I go from there?
Answer by richard1234(7193) About Me  (Show Source):
You can put this solution on YOUR website!
You do not even need to evaluate cos%5E%28-1%29+%281%2F2%29. The expression sec%28cos%5E%28-1%29%281%2F2%29%29 is equivalent to 1%2F%28cos%28cos%5E%28-1%29%281%2F2%29%29%29. Since cosine and arccosine are inverse functions, the end result is the argument of the function, or 1/2. Hence, it is equal to 1%2F%281%2F2%29, or 2.