Question

高三数学已知函数f(x)=a/x+bx

Answer 1

解由f(x)=a/x+bx=b(x+(a/b)/x)求导得f'(x)=b[x'+((a/b)/x)']=b(1-(a/b)/x^2)令f'(x)=0即1-(a/b)/x^2=0解得x=√(a/b)或x=-√(a/b)(舍去)当x属于（0,√(a/b)）时,f'(x)＜0,即f(x)在（0,√(a/b)）上减函数当x属于（√(a...