Using differentials, find the approximate value of the following up to 3 places of decimal.
√49.5
√49.5
Consider f(x)=√x⇒f′(x)=12√x
Let x = 49 and Deltax=0.5
Now f(x+Δx)≃f(x)+Δxf′(x)
∴√x+Δx≃√x+12√x×Δx
⇒√49.5≃√49+0.52√49=7+05140.=7+0.036⇒√49.5≃7.036