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Determine if the Mean Value Theorem for Integral applies to the function f(X) = x^3 - 16x on the interval [-1,1]. If so, find the X-coordinates of the point(s) guaranteed to exist by the theorem.

User Elliotrock
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2.6k points

1 Answer

13 votes
13 votes

Given:

Given that the function is


f(x)=x^3-16x

The interval is [-1,1].

Required:

To determine the mean value theorem for the given function.

Step-by-step explanation:

Since the function is continuous on [-1,1], the theorem does apply.

So, by the Mean Value Theorem for integrals, there is a number, c, in the interval (-1,1) such that


f(c)(1-(-1))=\int_(-1)^1f(x)dx
\begin{gathered} 2f(c)=\int_(-1)^1(x^3-16x)dx \\ \\ 2f(c)=[(1)/(4)x^4-(16x^2)/(2)]_(-1)^1 \\ \\ 2f(c)=[(1)/(4)-(1)/(4)]-[8-8] \\ \\ 2f(c)=0 \end{gathered}
\begin{gathered} 2(c^3-16c)=0 \\ \\ c^2-16=0 \\ \\ c=0,4,-4 \end{gathered}

The only value of c that is in the interval (-1,1) is


c=0

Final Answer:

The mean value theorem is applies the given function.

User Jon Barker
by
3.0k points
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