Confusing math problem

Well, not really but I forgot this stuff (AP Calc review)

cosx = -1/4 in the interval 0-pi
x = 104.478
but it's negative so its in quadrant 2 and 3
right?
so one answer is 255.522 (360 - 104.478) (1.5 something pi) <- quadraint 3


what would be the quadraint two answer and why?
thanks loves(:

well a more simple approach would be to understand that you should not use minus sign right at the beginning of your solution but work out a "base angle". . . .you should only take minus sign as an indicator of which quadrant your solution would lie in.

simply work out cos(inverse) of (1/4) . . .you get 75.522

now 75.522 is your base angle
since the sign is minus ur solution lies in 2nd or third quadrant

but your limit is from 0 to pi which only includes first and second quadrant so you will only get a single answer and that answer will lie in 2nd quadrant

the formula for working out ur solution in case of 2nd quadrant is

Answer = 180 - base angle so it becomes
= 180 - 75.522
= 104.478



(PS: had third quadrant been included in the limit you wouldve used the formula of 3rd quadrant which is 180 + base angle, and obtained your second answer as 255.522)

Hope this solves your problem :)