y=sin2x+sinxcosx=(1-cos2x)/2 + 1/2sin(2x)
=1/2+1/2(sin2x - cos2x)
=1/2+√2/2(√2/2sin2x - √2/2cos2x)
=1/2+√2/2sin(2x-π/4)
（1）最小正周期T=2π/2=π
（2）当0≤x≤π/2 设t=2x-π/4∈[-π/4,3π/4]
y=1/2+√2/2sin(t) ∈[0,(1+√2)/2]
当x=0 y=0 最小值
当x=3π/8 y=(1+√2)/2 最大值