Math question

[Pamela H in Texas]

From Lial's PreCalculus 4th ed, Pg 580, Problem 19

Original Problem: Find the exact circular function value for following:
http://i267.photobucket.com/albums/ii320/PadmeMaster/Theproblemitself.png

The work that is giving the wrong answer according to book:
http://i267.photobucket.com/albums/ii320/PadmeMaster/HowIworkedtheproblem.png

[kiana]

1) It looks like you're trying to find the remainder, so writing it as 3 and 5/6 pi. But a full circle is 2pi, so what you have here is 11/6 pi *more* than a full circle.

Then sec 23pi/6 = sec 11pi/6 = sec pi/6 (because the reference angle is pi/6, and 11pi/6 is in quadrant 4, where secant is positive)

It looks as though you may also have made an error in conversion -- 60 degrees is pi/3.

2) You really don't want to write sec 60deg = 5pi/6. The two quantities are not equal -- it is not a good habit to have mathematically.

[Pamela H in Texas]

Thanks. It took her a min but she figured it out thanks to your help :)