解1由f(x)=4coswx×sin(wx+∏/4)
=2×[sin((wx+π/4)+wx)+sin((wx+π/4)-wx)]
=2sin(2wx+π/4)+2sin(π/4)
=2sin(2wx+π/4)+√2
故T=2π/2w=π/w
又由T=π
即π/w=π
即w=1
(2)由f(x)=2sin(2x+π/4)+√2
由x属于[0,π/2]
则2x属于[0,π]
即2x+π/4属于[π/4,5π/4]
即2x+π/4属于[π/4,π/2],即x属于[0,π/8]时,f(x)=2sin(2x+π/4)+√2是增函数
2x+π/4属于[π/2,5π/4],即x属于[π/8,π/2]时,f(x)=2sin(2x+π/4)+√2是减函数.