Let f be the function defined as follows.
y=f(x)=(8x^2)-2x+3

(a) find the differential of f.
dy=(16x-2)dx
(b) use your result from part (a) to find the approximate change in y if x changes from 2 to 1.97. (round your answer to two decimal places.)
dy =

(c) find the actual change in y if x changes from 2 to 1.97 and compare your result with that obtained in part (b). (round your answer to two decimal places.)
δy =