(a)
The given equation can be rewritten as
$\rho \bullet \frac{d^{2}y}{dx^{2}} = \left\lbrack 1 + \left( \frac{dy}{dx} \right)^{2} \right\rbrack^{3/2}$
On squaring both sides, we get
$\left( \rho \bullet \frac{d^{2}y}{dx^{2}} \right) = \left\lbrack 1 + \left( \frac{dy}{dx} \right)^{2} \right\rbrack^{3}$
$\Rightarrow$ order = 2, degree = 2.