Question

102=8/a+8/a²+108/a³ 请问a=?用插值法求出

Answer 1

令 f(a)=8/a+8/a2+108/a3

a=1

f(a)=124;

a=1.1

f(a)=95.026;

a=1.05

f(a)=108.169;

a=1.07

f(a)=102.624;

a=1.072

f(a)=102.092;

a=1.0723

f(a)=102.012;

a=1.0724

f(a)=101.985;

a=1.07235

f(a)=101.999;

a=1.07234

f(a)=102.0017;

这是插值法,逐步逼近

a≈1.07234;还可以再往下更精确的计算