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8. Simpson's 3/8 rule example ( Enter your problem )
  1. Formula & Example-1 (table data)
  2. Example-2 (table data)
  3. Example-3 (table data)
  4. Example-4 `(f(x)=1/x)`
  5. Example-5 `(f(x)=1/(x+1))`
  6. Example-6 `(f(x)=x^3-2x+1)`
  7. Example-7 `(f(x)=2x^3-4x+1)`
Other related methods
  1. Left Riemann Sum
  2. Right Riemann Sum
  3. Midpoint Rule
  4. Left endpoint approximation
  5. Right endpoint approximation
  6. Trapezoidal rule
  7. Simpson's 1/3 rule
  8. Simpson's 3/8 rule
  9. Boole's rule
  10. Weddle's rule

3. Example-3 (table data)
(Previous example)
5. Example-5 `(f(x)=1/(x+1))`
(Next example)

4. Example-4 `(f(x)=1/x)`





Find the approximated integral value of an equation 1/x using Simpson's 3/8 rule
a = 1 and b = 2
Step value (h) = 0.25


Solution:
Equation is `f(x)=(1)/(x)`

`a=1`

`b=2`

The value of table for `x` and `f(x)`

`x``f(x)`
`x_0=1``f(x_(0))=f(1)=1`
`x_1=1.25``f(x_(1))=f(1.25)=0.8`
`x_2=1.5``f(x_(2))=f(1.5)=0.6667`
`x_3=1.75``f(x_(3))=f(1.75)=0.5714`
`x_4=2``f(x_(4))=f(2)=0.5`


Method-1:
Using Simpson's `3/8` Rule

`int f(x) dx=(3Delta x )/8 (f(x_(0))+2(f(x_(3))+f(x_(3))+...+f(x_(n-3)))+3(f(x_(1))+f(x_(2))+f(x_(4))+f(x_(5))+...+f(x_(2))+f(x_(n-1)))+f(x_(n)))`


`int f(x) dx=(3Delta x )/8 [f(x_(0))+3f(x_(1))+3f(x_(2))+2f(x_(3))+f(x_(4))]`

`f(x_(0))=1`

`3f(x_(1))=3*0.8=2.4`

`3f(x_(2))=3*0.6667=2`

`2f(x_(3))=2*0.5714=1.1429`

`f(x_(4))=0.5`

`int f(x) dx=(3xx0.25)/8 *(1+2.4+2+1.1429+0.5)`

`=(3xx0.25)/8 *(7.0429)`

`=0.6603`

Solution by Simpson's `3/8` Rule is `0.6603`



Method-2:
Using Simpson's `3/8` Rule

`int f(x) dx=(3Delta x )/8 (f(x_(0))+2(f(x_(3))+f(x_(3))+...+f(x_(n-3)))+3(f(x_(1))+f(x_(2))+f(x_(4))+f(x_(5))+...+f(x_(2))+f(x_(n-1)))+f(x_(n)))`


`int f(x) dx=(3Delta x )/8 [(f(x_(0))+f(x_(4)))+2(f(x_(3)))+3(f(x_(1))+f(x_(2)))]`

`=(3xx0.25)/8 [(1 +0.5)+2xx(0.5714)+3xx(0.8+0.6667)]`

`=(3xx0.25)/8 [(1 +0.5)+2xx(0.5714)+3xx(1.4667)]`

`=(3xx0.25)/8 [(1.5)+(1.1429)+(4.4)]`

`=0.6603`

Solution by Simpson's `3/8` Rule is `0.6603`




This material is intended as a summary. Use your textbook for detail explanation.
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3. Example-3 (table data)
(Previous example)
5. Example-5 `(f(x)=1/(x+1))`
(Next example)





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