SOLUTION: Given that y = 4x^2-x-4, find the approximate percentage change in y as x increases from 2 to 2.02.

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Question 1192303: Given that y = 4x^2-x-4, find the approximate percentage change in y as x increases from 2 to 2.02.
Answer by Edwin McCravy(20054) About Me  (Show Source):
You can put this solution on YOUR website!

y+=+4x%5E2-x-4

dy%2Fdx=8x-1

dy=%288x-1%29dx

x = 2, dx = Δx = 0.02

dy=%288%2A2-1%29%2A0.02

dy=0.3

dy is approximately Δy, so

the fractional change is approximately 
0.3/2 = 0.15 which equals the approximate
percentage change, 15%.

Edwin