(I)求f(x)的解析式;
(II)求函数 g(x)=f(x+π4)⋅f(x−π4) 在区间 [0,π2] 上的最大值及相应的x值.
如图,⊙O是△ABC的外接圆,弦AC的长为3,sinB=34,则⊙O的半径为( )
①作为生产关系的调整,简政放权能促进生产力发展
②简政放权通过变革上层建筑以适应经济基础发展
③简政放权是遵循社会发展规律的价值选择
④简政放权是解决我国基本矛盾的根本途径
⑴This is a photo of Hainan. ____
⑵I got to school by car yesterday.____
⑶Beijing is in the north of China.____
⑷The mountains are really beautiful.____
⑸I went to England last year.____