Let $x=1$ and $x+\delta x=1.04 \ \therefore \delta x = 0.04$

Also Let $y=3$ and $y+\delta y=3.01 \ \therefore \delta y=0.01$

Let $z=x^y \ \cdots \ \cdots (1)$

Differentiating partially w.r.t. to x

$\dfrac {\partial z}{\partial y} = yx^{y-1}$

Differentiating partially w.r.t. to y

$\dfrac {\partial z}{\partial y} = x^y …