A:I saw her half an hour ago.
B:I saw him an hour ago.
将二项式x+12x4n的展开式按x的降幂排列,若前三项系数成等差数列,则该展开式中x的指数是整数的项共有( )个
设集合A={0,1},集合B={x|x>a},若A∩B=∅,则实数a的范围是( )
已知sinα=35,α∈π2,π,则tanα+π4的值为____