SOLUTION: What is the exact value of cos x = -1/3. Show work. This actually comes from a much larger question, solve algebraically and give general solution in radians to {{{ 3 sin^2 (x)

Algebra ->  Trigonometry-basics -> SOLUTION: What is the exact value of cos x = -1/3. Show work. This actually comes from a much larger question, solve algebraically and give general solution in radians to {{{ 3 sin^2 (x)      Log On


   



Question 902198: What is the exact value of cos x = -1/3. Show work.
This actually comes from a much larger question, solve algebraically and give general solution in radians to +3+sin%5E2+%28x%29+%2B+5+cos+%28x%29+=+1+ . Once I get to the factors of (3cos x +1) and (cos x - 2), I know that x cannot equal 2, so that leaves cos x = -1/3. I need the exact values for this, in terms of the unit circle.
Thanks, much appreciated!

Answer by Fombitz(32388) About Me  (Show Source):
You can put this solution on YOUR website!
Use the inverse cosine or acos button on your calculator.
cos%5E%28-1%29%28-1%2F3%29=109.47 degrees and
cos%5E%28-1%29%28-1%2F3%29=250.53 degrees