IDNLearn.com: Where questions are met with accurate and insightful answers. Our platform is designed to provide quick and accurate answers to any questions you may have.

Question:

Find the average value of [tex]$f(x)=\frac{6 x}{5}-1$[/tex] over the interval [tex]\left[-\frac{13}{6}, \frac{23}{6}\right][/tex].

Submit your answer as an exact value.

Provide your answer below:
Average Value [tex]=$\square$[/tex]


Sagot :

To find the average value of the function [tex]\( f(x) = \frac{6x}{5} - 1 \)[/tex] over the interval [tex]\(\left[-\frac{13}{6}, \frac{23}{6}\right] \)[/tex], we can use the formula for the average value of a function over an interval [tex]\([a, b]\)[/tex]:

[tex]\[ \text{Average Value} = \frac{1}{b-a} \int_a^b f(x) \, dx \][/tex]

Here, our interval [tex]\([a, b]\)[/tex] is [tex]\(\left[-\frac{13}{6}, \frac{23}{6}\right]\)[/tex]. So, [tex]\( a = -\frac{13}{6} \)[/tex] and [tex]\( b = \frac{23}{6} \)[/tex].

Now, let's compute the integral [tex]\(\int_a^b f(x) \, dx\)[/tex]:

[tex]\[ \int_{-\frac{13}{6}}^{\frac{23}{6}} \left( \frac{6x}{5} - 1 \right) dx \][/tex]

We can split this integral into two parts:

[tex]\[ \int_{-\frac{13}{6}}^{\frac{23}{6}} \left( \frac{6x}{5} \right) dx - \int_{-\frac{13}{6}}^{\frac{23}{6}} 1 \, dx \][/tex]

First, evaluate [tex]\( \int_{-\frac{13}{6}}^{\frac{23}{6}} \frac{6x}{5} \, dx \)[/tex]:

[tex]\[ \int_{-\frac{13}{6}}^{\frac{23}{6}} \frac{6x}{5} \, dx = \frac{6}{5} \int_{-\frac{13}{6}}^{\frac{23}{6}} x \, dx \][/tex]

The integral of [tex]\( x \)[/tex] is [tex]\(\frac{x^2}{2}\)[/tex], so:

[tex]\[ \frac{6}{5} \left[ \frac{x^2}{2} \right]_{-\frac{13}{6}}^{\frac{23}{6}} = \frac{6}{5} \left( \frac{\left(\frac{23}{6}\right)^2}{2} - \frac{\left(\frac{13}{6}\right)^2}{2} \right) \][/tex]

Calculating each term separately:

[tex]\[ \left(\frac{23}{6}\right)^2 = \frac{529}{36}, \quad \left(\frac{13}{6}\right)^2 = \frac{169}{36} \][/tex]

Thus,

[tex]\[ \frac{6}{5} \left( \frac{529}{36 \cdot 2} - \frac{169}{36 \cdot 2} \right) = \frac{6}{5} \left( \frac{529 - 169}{72} \right) = \frac{6}{5} \left( \frac{360}{72} \right) = \frac{6}{5} \left( 5 \right) = 6 \][/tex]

Next, evaluate [tex]\( \int_{-\frac{13}{6}}^{\frac{23}{6}} 1 \, dx \)[/tex]:

[tex]\[ \int_{-\frac{13}{6}}^{\frac{23}{6}} 1 \, dx = \left[ x \right]_{-\frac{13}{6}}^{\frac{23}{6}} = \frac{23}{6} - \left(-\frac{13}{6}\right) = \frac{23}{6} + \frac{13}{6} = \frac{36}{6} = 6 \][/tex]

Putting everything together:

[tex]\[ \int_{-\frac{13}{6}}^{\frac{23}{6}} \left( \frac{6x}{5} - 1 \right) dx = 6 - 6 = 0 \][/tex]

Finally, divide by the length of the interval, [tex]\( b - a \)[/tex]:

[tex]\[ b - a = \frac{23}{6} - \left(-\frac{13}{6}\right) = \frac{36}{6} = 6 \][/tex]

[tex]\[ \text{Average Value} = \frac{1}{b-a} \int_a^b f(x) \, dx = \frac{1}{6} \times 0 = 0 \][/tex]

Thus, the average value of the function [tex]\( f(x) = \frac{6x}{5} - 1 \)[/tex] over the interval [tex]\(\left[-\frac{13}{6}, \frac{23}{6}\right]\)[/tex] is:

[tex]\[ \boxed{0} \][/tex]