Answer
$8.0625$
Work Step by Step
The expression for $y$ can be written as: $y=x^{0.5}$
Now, $\dfrac{dy}{dx}=0.5x^{-0.5}$
or, $dy=0.5x^{-0.5} dx$
Next, we have: $dy=0.5 \times (64)^{-0.5}(1)=0.0625$
So, the new $y$ value is equal to $0.0625+(64)^{0.5}=8.0625$
