—I've never seen a person with a better of art.
设函数f(x)=2cos(ωx+φ)对任意的x都有fπ4+x=fπ4-x,若设函数g(x)=3sin(ωx+φ)﹣1,则gπ4的值是____
求不等式组 {5(x−1)−1<3x1+2x3≥x−1 的非负整数解.