Debbie is growing fast. She is even than her mother .
类推是学习化学的一种重要方法。下列类推正确的是 ( )
已知﹣ π2 <x<0,则sinx+cosx= 15 .
(I)求sinx﹣cosx的值;
(Ⅱ)求 3sin2x2−2sinx2cosx2+2x2tanx+1tanx 的值.