5. Applications of Derivatives

If $f\(\left\)(x\(\right\))=x^3-8x+6$, find the differential $dy$ when x = 2 and $dx = 0.2$.

If $f\(\left\)(x\(\right\))=\(\sqrt{x+2}\)$, find the differential $dy$ when $x=2$ and $dx = 0.01$.