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5. Secant method example ( Enter your problem )
  1. Algorithm & Example-1 `f(x)=x^3-x-1`
  2. Example-2 `f(x)=2x^3-2x-5`
  3. Example-3 `x=sqrt(12)`
  4. Example-4 `x=root(3)(48)`
  5. Example-5 `f(x)=x^3+2x^2+x-1`

3. Example-3 `x=sqrt(12)`





Find `sqrt(12)` using Secant method

Solution:
Let `x=sqrt(12)`

`:.x^2=12`

`:.x^2-12=0`

i.e. `f(x)=x^2-12`

Here
`x`01234
`f(x)`-12-11-8-34



`1^(st)` iteration :

`x_0 = 3` and `x_1 = 4`

`f(x_0) = f(3) = -3` and `f(x_1) = f(4) = 4`

`:. x_2 = x_0 - f(x_0) * (x_1 - x_0)/(f(x_1) - f(x_0))`

`x_2 = 3 - (-3) * (4 - 3)/(4 - (-3))`

`x_2 = 3.4286`

`:. f(x_2)=f(3.4286)=3.4286^2-12=-0.2449`


`2^(nd)` iteration :

`x_1 = 4` and `x_2 = 3.4286`

`f(x_1) = f(4) = 4` and `f(x_2) = f(3.4286) = -0.2449`

`:. x_3 = x_1 - f(x_1) * (x_2 - x_1)/(f(x_2) - f(x_1))`

`x_3 = 4 - 4 * (3.4286 - 4)/(-0.2449 - 4)`

`x_3 = 3.4615`

`:. f(x_3)=f(3.4615)=3.4615^2-12=-0.0178`


`3^(rd)` iteration :

`x_2 = 3.4286` and `x_3 = 3.4615`

`f(x_2) = f(3.4286) = -0.2449` and `f(x_3) = f(3.4615) = -0.0178`

`:. x_4 = x_2 - f(x_2) * (x_3 - x_2)/(f(x_3) - f(x_2))`

`x_4 = 3.4286 - (-0.2449) * (3.4615 - 3.4286)/(-0.0178 - (-0.2449))`

`x_4 = 3.4641`

`:. f(x_4)=f(3.4641)=3.4641^2-12=0.0001`


Approximate root of the equation `x^2-12=0` using Secant method is `3.4641` (After 3 iterations)

`n``x_0``f(x_0)``x_1``f(x_1)``x_2``f(x_2)`Update
13-3443.4286-0.2449`x_0 = x_1`
`x_1 = x_2`
2443.4286-0.24493.4615-0.0178`x_0 = x_1`
`x_1 = x_2`
33.4286-0.24493.4615-0.01783.46410.0001`x_0 = x_1`
`x_1 = x_2`







This material is intended as a summary. Use your textbook for detail explanation.
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