已知角α的终边与单位圆x2+y2=1交于P(,y),则sin(+2α)=( )
有穷数列5,8,11,…,的项数是().
在中,若,则等于()
若tan(+)="3," tan(-)="5," 则tan2=()
函数的周期为( )
的值为( )