f(x)在x=0的领域内有二阶导数,又x→0时lim((sinx+xf(x))\x3)=0,求f(0),f'(0),f''(0)

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f(x)在x=0的领域内有二阶导数,又x→0时lim((sinx+xf(x))\x3)=0,求f(0),f'(0),f''(0)
f(x)在x=0的领域内有二阶导数,又x→0时lim((sinx+xf(x))\x3)=0,求f(0),f'(0),f''(0)

f(x)在x=0的领域内有二阶导数,又x→0时lim((sinx+xf(x))\x3)=0,求f(0),f'(0),f''(0)
sinx=x+(1/3!)x³+0(x³)
f(x)=f(0)+f′(0)x+f″(0)x²+0(x³)
xf(x)=f(0)x+f′(0)x²+f″(0)x³+0(x³)
sinx+xf(x)=(1+f(0))x+f′(0)x²+[(1/3!)+f″(0)]x³+0(x³)
lim((sinx+xf(x))\x3)=0,
1+f(0)=0 f′(0)=0 (1/3!)+f″(0)=0
f(0)=-1 f′(0)=0 f″(0)=-(1/3!)