Question 85483
The question is, find the average rate of change from f from -2 to 2.  What is the average rate of change of f from x1 to x2, where x1 and x2 are distinct real numbers?
f(x) = (-1/4)x
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The average for f(x) as x goes from a to b is [f(b)-f(a)]/[b-a] 
which is the same as the slope of a line thru  points (a,f(a)), (b,f(b))
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Your Problem:
Average from -2 to 2 is [f(2)-f(-2)]/[2--2] 
=[(-1/4)*2 - (-1/4)(-2)]/[4]
=[-1/2 - (1/2)]/4
= [-1/4]
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Average from x1 to x2 
= [(-1/4)(x1+x2)]/[x1-x2]
 = [-1/4]
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Cheers,
Stan H.