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6. Trapezoidal 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

1. Formula & Example-1 (table data)
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3. Example-3 (table data)
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2. Example-2 (table data)





Find the approximated integral value using Trapezoidal rule
xf(x)
0.01.0000
0.10.9975
0.20.9900
0.30.9776
0.40.8604


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

`x``f(x)`
`x_0=0``f(x_(0))=1`
`x_1=0.1``f(x_(1))=0.9975`
`x_2=0.2``f(x_(2))=0.99`
`x_3=0.3``f(x_(3))=0.9776`
`x_4=0.4``f(x_(4))=0.8604`


Method-1:
Using Trapezoidal Rule
`int f(x) dx=(Delta x )/2 (f(x_(0))+2(f(x_(1))+f(x_(2))+f(x_(3))+...+f(x_(n-1)))+f(x_(n)))`


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

`f(x_(0))=1`

`2f(x_(1))=2*0.9975=1.995`

`2f(x_(2))=2*0.99=1.98`

`2f(x_(3))=2*0.9776=1.9552`

`f(x_(4))=0.8604`

`int f(x) dx=0.1/2*(1+1.995+1.98+1.9552+0.8604)`

`=0.1/2*(7.7906)`

`=0.3895`

Solution by Trapezoidal Rule is `0.3895`



Method-2:
Using Trapezoidal Rule
`int f(x) dx=(Delta x )/2 (f(x_(0))+2(f(x_(1))+f(x_(2))+f(x_(3))+...+f(x_(n-1)))+f(x_(n)))`


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

`=0.1/2 [1 +0.8604 + 2xx(0.9975+0.99+0.9776)]`

`=0.1/2 [1 +0.8604 + 2xx(2.9651)]`

`=0.1/2 [1 +0.8604 + 5.9302]`

`=0.3895`

Solution by Trapezoidal Rule is `0.3895`




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