Determine the order and degree of the differential equations. State also whether they are linear or non-linear. 

$\frac{d^{2}y}{d{x}^2}+4y=0$

Determine the order and degree of the differential equations. State also whether they are linear or non-linear.

${\left(\frac{dy}{dx}\right)}^2+\frac{1}{{\displaystyle \frac{dy}{dx}}}=2$

Determine the order and degree of the differential equations. State also whether they are linear or non-linear.

$\sqrt{1+{\left(\frac{dy}{dx}\right)}^2}={\left(c\frac{d^{2}y}{d{x}^2}\right)}^{\frac{1}{3}}$

Determine the order and degree of the differential equations. State also whether they are linear or non-linear.

$\frac{d^{2}y}{d{x}^2}+{\left(\frac{dy}{dx}\right)}^2+xy=0$

Determine the order and degree of each of the following differential equations. State also whether they are linear or non-linear.

$\sqrt[3]{\frac{d^{2}y}{d{x}^2}}=\sqrt{\frac{dy}{dx}}$

Determine the order and degree of the differential equations. State also whether they are linear or non-linear.

$\frac{d^{4}y}{d{x}^4}={\left\{c+{\left(\frac{dy}{dx}\right)}^2\right\}}^{3/2}$

Determine the order and degree of the differential equations. State also whether they are linear or non-linear.

$y\frac{d^{2}x}{d{y}^2}=y^2+1$

Determine the order and degree of the differential equations. State also whether they are linear or non-linear.

$s^2\frac{d^{2}t}{d{s}^2}+st\frac{dt}{ds}=s$