f'(x)=3x²+2ax+b(1) 由条件,f'(1)=3+2a+b=3,f'(2/3)=4/3+4a/3 +b=0解得 a=2,b=-4(2)于是 f'(x)=3x²+4x-4=(3x-2)(x+2)令f'(x)≥0,解得x≤-2或x≥2/3即f(x)的增区间为(-∞,-2]和[2/3,+∞)由于 f(x)在区间[m,...