Question

曲线y=2sin(x+)cos(x-)与直线y=在y轴右侧的交点按横坐标从小到大依次记为P₁，P₂，P₃，…，则|P₂P₄|等于

A.π                   B.2π                  C.3π                 D.4π

Answer 1

解析：y=2sin(x+)cos(x)

=2sin(x+)sin(+x)

=2sin²(x+)

=1-cos(2x+)

=1+sin2x.

周期为T==π,P₂与P₄间的距离为一个周期，故选A.

答案：A