A:y=4x+12+3
B:y=4x-12+3
C:y=4x+12-3
D:y=4x-12-3
(Ⅰ)求 tanx 的值;
(Ⅱ)求 sin2x−cos2x 的值.
The little girl drew a tree and _____ it _____. The tree was nice.