y=x²sin(1/x²)=(x²)'·sin(1/x²)+x²·[sin(1/x²)]'=2x·sin(1/x²)+x²·cos(1/x²)·(1/x²)'=2x·sin(1/x²)+x²·cos(1/x²)·(-2)·(1/x³)=2x·sin(1/x²)-(2/x)·cos(1/x²)
签字坪匣餐桌蹬灿
