F(x)=2+√2sin〖(2x+π/4)〗\x05f(x)_max=2+√2,此时,sin(2x+π/4)=1,所以2x+π/4=π/2+2kπ(k为一切整数)所以x的集合为{x︱x=π/8+kπ}(2)G(x)=sint在[-π/2+2kπ,π/2+2kπ]上单调递增,在[π/2+2kπ,3π/2+2kπ]上单调递减所以f(x)在[-3π/8+kπ,π/8+kπ]上单调递增,在[π/8+kπ,5π/8+kπ]上单调递减