http://i187.photobucket.com/albums/x22/cshung/7008080102888.png
(For Q2)
There is a bug in the proof, can you find it? :p
2008-08-02 18:48:37 補充:
既然你搵到了咁即係你識做啦
分番晒case就得,太煩唔做了。
2008-08-05 20:12:39 補充:
Let S = sin(y/2 + pi/8)
C = cos(y/2 + pi/8)
Case 1: S is positive, C is positive, S >= C => |S - C| = S - C
Case 2: S is positive, C is positive, S < C => |S - C| = C - S
Case 3: S is positive, C is negative => |S - C| = S + C
Case 4: S is negative, C is positive => |S - C| = -S - C
2008-08-05 20:12:46 補充:
Case 5: S is negative, C is negative, S >= C => |S - C| = S - C
Case 6: S is negative, C is negative, S < C => |S - C| = C - S
Notice, Case 1 = Case 5, Case 2 = Case 6, there are really just 4 cases.
You can represent the solution with all these cases.