0
8.3kviews
Find a root of the equation $x^{3}+x-1=0$ correct to three decimal places, by the method of False Position.
1 Answer
written 2.5 years ago by |
Solution:
$ \begin{aligned} &\longrightarrow \text { Here } f(x)=x^{3}+x-1=0 \\\\ &\text { At } x=0, f(0)=-1(\text {-ve) } \\\\ &x=1, f(1)=1(\text { tve }) \\ \end{aligned} $
$\therefore$, The root lies between 0 and 1.
$ \text { Take } \begin{array}{rl} x_{0}=0 & x_{1}=1 \\\\ f\left(x_{1}\right)=-1 & f\left(x_{1}\right)=1 \\ \end{array} $
sr.no | $x_(i)$ | $f(x_i)$ | $x_(i-1)$ | $ f(x_(i-1))$ | $x_(i+1)$ | $f(x_(i+1))$ |
---|---|---|---|---|---|---|
1 | 1 | 1 | 0 | -1 | 0.5 | -0.375 < 0 |
2 | 1 | 1 | 0.5 | -0.375 | 0.636 | -0.1067 < 0 |
3 | 1 | 1 | 0.636 | -0.1067 | 0.6711 | -0.02665 < 0 |
4 | 1 | 1 | 0.6711 | -0.02665 | 0.6796 | -0.00652 |
5 | 1 | 1 | 0.6796 | -0.00652 | 0.68168 | -0.0015517 |
6 | 1 | 1 | 0.68168 | -0.0013517 | 0.68217 | -0.000378 |
7 | 1 | 1 | 0.68217 | -0.000378 | 0.6822 |
The desired root correct to three decimal places is 0.6822.