Letfbe the function defined as follows.

y=f(x)=8x^2 - 4x +6

(a) Find the differential off. dy=

(b) Use your result from part (a) to find the approximate change inyifxchanges from 2 to 1.97. (Round your answer to two decimal places.) dy= (c) Find the actual change inyifxchanges from 2 to 1.97 and compare your result with that obtained in part (b). (Round your answer to two decimal places.) y=