The approximate volume of a cube of side a meters on increasing the s…

x = side of cube

so volume = $V(x) = x^3$

$x=a$

$\frac{dV(x)}{dx}=3x^2$

now $x = a +4\%a=1.04a$

$V(x+dx)=V(x)+\frac{d(V(x))}{dx}×Δx$

$Δx=\frac{4a}{100}$

$⇒a^3+3a^2×\frac{4a}{100}$

$=\frac{112}{100}a^3m^3=1.12a^3\,m^3$