Question

这题怎么做？求函数的零点。

Answer 1

反值两点取中点，作为下一逼近解：

f（3）=-2，f（4）=6
f((3+4)/2)=f(3.5)=0.625
f(3.25)=-0.984375
f（3.375）=-0.259765625
f（3.4375）=0.1618652344
f(3.40625)=-0.05404663086
精确到0.1，x≈3.4

f(3.421875)=0.05262374878
!f(3.4140625)=-0.001031398773
f(3.41796875)=0.02571600676
f(3.416015625)=0.01232228428
f(3.4150390625)=0.005640440621
f(3.41455078125)=0.00230327074
f(3.414306640625)=0.0006356234808
f(3.4141845703125)=-0.0001979657663
f(3.41424560546875)=0.0002188093266
x≈3.4142