Question

Graph the function f(x)=x+4/x

Graph the secant line that passes through the points (1,5) and (8,8.5) on the same set of axes

Find the number c that satisfies the conclusion of the Mean Value Theorem for f on [1,8]

c=

Notice that if you graph the tangent line to the point (c,f(c)) it is parallel to the secant line.

Answers

so, did you do that, and notice the parallel lines? That means that for some c between 1 and 8,

f'(x) = (8.5-5)/(8-1)

So, you need to find c where

-4/c^2 = 1/2

Eh? Not possible. Looks like (8,8.5) is not on the curve. Better fix you point and redo the steps.

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