Let f(x)=−log(4x)+5.
What is the average rate of change of f(x) from 3 to 8?
Round your answer to the nearest hundredth.
We want to find this :
[ -log (4*8) + 5 - ( - log(4*3) + 5) ] / [ 8 - 3 ] =
[ - log(4*8) + log (4*3) ] / [ 8 - 3 ] =
[ log (12) - log (32) ] / 5 =
[ using log a - log b = log (a/b) ]
log ( 12 / 32) / 5 ≈ -0.085 ≈ -0.09
+524 
