Skip to main content
Ch. 5 - Integrals
Hass - Thomas' Calculus 15th Edition
Hass15th EditionThomas' CalculusISBN: 9780137616077Not the one you use?Change textbook
Chapter 5, Problem 5.PE.70a

Find the average value of
__
a. y = √3x over [0, 3]

Verified step by step guidance
1
Identify the function and the interval over which to find the average value. Here, the function is \(y = \sqrt{3x}\) and the interval is \([0, 3]\).
Recall the formula for the average value of a function \(f(x)\) over the interval \([a, b]\): \[\text{Average value} = \frac{1}{b - a} \int_a^b f(x) \, dx\]
Substitute the given function and interval into the formula: \[\text{Average value} = \frac{1}{3 - 0} \int_0^3 \sqrt{3x} \, dx = \frac{1}{3} \int_0^3 (3x)^{1/2} \, dx\]
Simplify the integrand if possible and set up the integral for evaluation: \[\int_0^3 (3x)^{1/2} \, dx = \int_0^3 3^{1/2} x^{1/2} \, dx = \sqrt{3} \int_0^3 x^{1/2} \, dx\]
Evaluate the integral \(\int_0^3 x^{1/2} \, dx\) using the power rule for integration: \[\int x^{n} \, dx = \frac{x^{n+1}}{n+1} + C\] Apply this with \(n = \frac{1}{2}\) and then multiply by \(\sqrt{3}\) and finally multiply by \(\frac{1}{3}\) to find the average value.

Verified video answer for a similar problem:

This video solution was recommended by our tutors as helpful for the problem above.
Video duration:
4m
Was this helpful?

Key Concepts

Here are the essential concepts you must grasp in order to answer the question correctly.

Average Value of a Function

The average value of a function f(x) over an interval [a, b] is given by (1/(b - a)) times the definite integral of f(x) from a to b. It represents the mean height of the function on that interval.
Recommended video:
06:37
Average Value of a Function

Definite Integral

A definite integral calculates the net area under the curve of a function between two points a and b. It is essential for finding accumulated quantities and is used here to find the total 'sum' of function values over the interval.
Recommended video:
05:43
Definition of the Definite Integral

Integration of Power Functions

Integrating functions like y = √(3x) involves rewriting the function in exponent form and applying the power rule for integration, which states ∫x^n dx = (x^(n+1))/(n+1) + C, for n ≠ -1.
Recommended video:
07:32
Representing Functions as Power Series