已知函数f（x）=4x^2-mx+5,当x∈（-2,正无穷大）时是增函数,x∈（负无穷大,-2）时是减函数,所以顶点x=-2 m/8=-2 m=-16
f（x）=4x^2+16x+5
f(1)=4+16+5=25