How many ____ are there?(正方形)
已知|φ=2kπ+π3|=2, |φ=π3|=1,y=3sin(2x+π3),则向量-π2+2kπ≤2x+π3≤π2+2kπ在kπ-512π≤x≤kπ+π12方向上的投影是( )
(1) (2) (3) (4)
____