Using differentials, find the approximate value of each of the following up to 3 places of decimal.

Consider y =


Let x = 256 and Δx = -1. Then, we get


Δy = (x+∆x)1/4 - (x)1/4


= (225)1/4 - (256)1/4


= (225)1/4 - 4


= (225)1/4 = Δy + 4


Now, dy is approximately equal to Δy and is given by:




= -0.0039


Therefore, the approximate value of (255)1/4 is 3.9961.


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