Verifying Int. of f(x) Using Trapezoid Rule

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SUMMARY

The forum discussion centers on verifying the calculation of the integral of the function $$f(x)$$ using the trapezoid rule. The user initially calculated the integral $$\int^{1.25}_0 f(x) \, dx$$ and arrived at an approximate value of $$4.5605$$. However, it was pointed out that the constant factor should be $$0.125$$, leading to a corrected result of approximately $$2.28025$$. This highlights the importance of accurately applying the trapezoid rule in numerical integration.

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shamieh
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Just need someone to verify my solution and that I have done my calculations correctly. Thank you again for all of your help in advance, everyone on this forum has helped me SO much with my classes this semester.

Using the trapezoid rule.

The following data was collected about the function $$f(x)$$

Estimate $$\int^{1.25}_0 f(x) \, dx$$

$$x | f(x)$$

$$0 | 3.000$$

$$.25 | 2.540$$

$$.50 | 1.583$$

$$.75 | 1.010$$

$$1.00 | 1.346$$

$$1.25 | 2.284$$

I ended up with $$.25[3.000 + 2(2.540) + 2(1.583) + 2(1.010) + 2(1.346) + 2.284] \approx 4.5605$$
 
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The constant in front should be:

$$\frac{b-a}{2n}=\frac{1.25-0}{2\cdot5}=0.125$$

Your result is twice as large as it should be. :D
 
MarkFL said:
The constant in front should be:

$$\frac{b-a}{2n}=\frac{1.25-0}{2\cdot5}=0.125$$

Your result is twice as large as it should be. :D

I knew something didn't look right...lol
Thanks Mark!

- - - Updated - - -

so does $\approx 2.28025$ look more accurate?
 
Yes, that looks good. :D
 

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