SOLUTION: An explanation to my question would be greatly appreciated. I have many of these problems to do and Im not sure how to do it. I am allowed to use excel, so i am able to get parti

Algebra ->  Trigonometry-basics -> SOLUTION: An explanation to my question would be greatly appreciated. I have many of these problems to do and Im not sure how to do it. I am allowed to use excel, so i am able to get parti      Log On


   



Question 813716: An explanation to my question would be greatly appreciated. I have many of these problems to do and Im not sure how to do it. I am allowed to use excel, so i am able to get partial answer, but there are two answers to my questions, and I dont know how to get the second one. Please help.
Solve: Cos(x) = 0.5, give all answers between 0 thru 360 degrees.
I know that I can take the inverse and get an answer of 60 degrees. But the answers in the book are telling me that there is a second answer, being 300 degrees. How do I get the second answer? PS: I got the 60 degrees from Excel.
Thanks for your time, this site is so very helpful. Sherry

Answer by MathTherapy(10552) About Me  (Show Source):
You can put this solution on YOUR website!

An explanation to my question would be greatly appreciated. I have many of these problems to do and Im not sure how to do it. I am allowed to use excel, so i am able to get partial answer, but there are two answers to my questions, and I dont know how to get the second one. Please help.
Solve: Cos(x) = 0.5, give all answers between 0 thru 360 degrees.
I know that I can take the inverse and get an answer of 60 degrees. But the answers in the book are telling me that there is a second answer, being 300 degrees. How do I get the second answer? PS: I got the 60 degrees from Excel.
Thanks for your time, this site is so very helpful. Sherry

The POSITIVE reference angle of cos (x) = 1%2F2, or .5 is in the 4th quadrant where cos in POSITIVE. This degree measure is 5pi%2F3, or highlight_green%28300%5Eo%29. You can verify this by checking the unit circle.

You can do the check!!

Send comments, “thank-yous,” and inquiries to “D” at MathMadEzy@aol.com. Further help is available, online or in-person, for a fee, obviously.

For FREE info and answers to questions about the ASVAB exam, the NYS 3 – 8 city/state wide exams, GENERAL MATH QUESTIONS, MATH HOMEWORK QUESTIONS, or MATH QUESTIONS related to the Regents Integrated Algebra, Regents Geometry, Regents Algebra 2/Trigonometry, SHSAT, COOP/HSPT/TACHS, PSAT, SAT, ACT, SSAT/ISEE, GRE, CLEP, and the GED, you can visit: http://asvabstudyzone.freeforums.net/.