题目

In after-school activities,students are       into different groups accirdubg to their interests．       A．In addition           B．provided              C．collected                D．appointed 答案：A 解析: 略已知f（x）=(sinx+cosx)22+2sin2x-cos22x，若f（3π8+α2）=1318，f（π8-β2）=5，且0＜α＜π4，π4＜β＜3π4，则sin（α+β）的值为 ．