牛顿迭代法又称牛顿-拉夫逊方法,它是牛顿在17世纪提出的一种在实数集上近似求解方程根的一种方法,具体步骤如下:设r是函数y=f(x)的一个零点,任意选取x₀作为r的初始近似值,以点(x₀,f(x₀))为切点作曲线y=f(x)的切线l₁,设l₁与x轴交点的横坐标为x₁,并称x₁为r的1次近似值;以点(x₁,f(x₁))为切点作曲线y=f(x)的切线l₂,设l₂与x轴交点的横坐标为x₂,称x₂为r的2次近似值,以点(
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)为切点作曲线y=f(x)的切线l
n+1 , 记l
n+1与x轴交点的横坐标为x
n+1,设、f(x)=x³+2x-2(x≥0)的零点为r,取x₀=0,则r的2次近似值为:
设
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数列{a
n}的前n项积为Tn.若任意的;n∈N*,Tn<λ恒成立,则整数λ的最小值为
.