Calculating the Average Value of a Function Between Two Limits

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SUMMARY

The average value of the function 1/x between the limits x=2/3 and x=8/3 is calculated using the formula 1/(b-a) ∫f(x) dx. The solution involves evaluating the integral of 1/x, resulting in 1/2 * (ln x) evaluated at the specified limits. The final result simplifies to ln(2), confirming the correctness of the calculations presented in the discussion.

PREREQUISITES
  • Understanding of integral calculus
  • Familiarity with the natural logarithm function
  • Knowledge of definite integrals
  • Ability to manipulate algebraic expressions
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  • Study the properties of definite integrals
  • Learn about the application of the average value theorem for integrals
  • Explore advanced integration techniques, including substitution methods
  • Review logarithmic identities and their applications in calculus
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Students in calculus courses, mathematics educators, and anyone interested in understanding the application of integrals in calculating average values of functions.

Justabeginner
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Homework Statement


What is the average value of a function 1/x between x=2/3 and x=8/3?


Homework Equations


1/(b-a) ∫f(x) dx with a and b being the lower and upper limits, respectively


The Attempt at a Solution



1/([8/3] - [2/3])∫1/x dx
1/(6/3) ∫1/x dx
1/2 ∫1/x dx
1/2 * (ln x)

Plug in:
(ln {8/3})/2 - (ln {2/3}/2)
ln 4/2
ln 2

Is this correct? Thanks :)
 
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Justabeginner said:

Homework Statement


What is the average value of a function 1/x between x=2/3 and x=8/3?


Homework Equations


1/(b-a) ∫f(x) dx with a and b being the lower and upper limits, respectively


The Attempt at a Solution



1/([8/3] - [2/3])∫1/x dx
1/(6/3) ∫1/x dx
1/2 ∫1/x dx
1/2 * (ln x)

Plug in:
(ln {8/3})/2 - (ln {2/3}/2)
ln 4/2
ln 2

Is this correct? Thanks :)
Looks good.

Though, just to be clear, your reasoning for your last few steps was ##\frac{1}{2}\ln\left(\frac{(\frac{8}{3})}{(\frac{2}{3})}\right) = \frac{1}{2}\ln(4) = \ln(4^{\frac{1}{2}}) = \ln2##, correct?
 
Yes, that is exactly what I have written on my paper here. Thank you so much for your help :)
 

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