Find the average value of the function f(x)=|4x| on the interval [−1,1] and determine a number c in this interval for which f(x) is equal to the average value.

Respuesta :

Answer:

Average value A = 2

c = 0.5 or c = -0.5

Step-by-step explanation:

The average value A of a function f(x) between the points (a,b) is given by

[tex]A = \frac{1}{b-a}\int\limits^b_a {f(x)} \, dx  [/tex]

You have [tex]f(x) = |4x|[/tex].

From the definition of the module equation, we have that:

[tex]\left \{ {{|f(x)|=f(x), f(x) \geq 0} \atop {|f(x)|= - f(x), f(x) < 0}} \right [/tex]

So

[tex]\left \{ {{|4x|=4x, x \geq 0} \atop {|4x|= - 4x, x < 0}} \right[/tex]

The average value will then be

[tex]A = \frac{1}{1-(-1)} \int\limits^0_{-1} {-4x} \, dx + \int\limits^1_{0} {4} \, dx [/tex]

[tex]A = \frac{1}{2} {\int\limits^0_{-1} {-4x} \, dx + \int\limits^1_{0} {4x} \, dx}[/tex]

[tex]A = \frac{4}{2} [/tex]

So the average value A = 2.

As for the second question

|4x| = 2 when

4x = 2 or 4x = -2

x = 0.5 or x = -0.5

So there are two values of c in this interval that are equal to the average value: c = 0.5 or c = -0.5

We will see that the average is equal to 0.

How to find the average?

For a function f(x) we define the average in an interval [a, b] as:

[tex]\frac{f(b) - f(a)}{b - a}[/tex]

In this case we have:

f(x) = |4x|

And the interval is [-1, 1]

Replacing that we get:

[tex]\frac{|4*1| - |4*-1|}{1 - (-1)} = 0[/tex]

So the average of the function f(x) = |4x| on the given interval is 0.

If you want to learn more about averages, you can read:

https://brainly.com/question/8728504

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