Using differentials, find the approximate value of each of the following up to 3 places of decimal.
Consider y =
Let x = 81 and Δx = 1. Then, we get
Δy =
=
⇒ = Δy + 3
Now, dy is approximately equal to Δy and is given by:
dy =
= 0.009
Therefore, the approximate value of is 3.009.