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75

The degree of the differential equation $\frac{d^2 y}{d x^2}+e^{d y / d x}=0$ is ............ .

Explanation

Given differential equation is

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

Degree of this equation is not defined.

76

The degree of the differential equation $\sqrt{1+\left(\frac{d y}{d x}\right)^2}=x$ is ................. .

Explanation

Given differential equation is $\sqrt{1+\left(\frac{d y}{d x}\right)^2}=x$

So, degree of this equation is two.

77

The number of arbitrary constants in the general solution of a differential equation of order three is .......... .

Explanation

There are three arbitrary constants.

78

$\frac{d y}{d x}+\frac{y}{x \log x}=\frac{1}{x}$ is an equation of the type ........... .

Explanation

Given differential equation is $\frac{d y}{d x}+\frac{y}{x \log x}=\frac{1}{x}$

The equation is of the type $\frac{d y}{d x}+P y=Q$

79

General solution of the differential equation of the type is given by ............ .

Explanation

Given differential equation is

$$\frac{d x}{d y}+P_1 x=Q_1$$

The general solution is

$$x \cdot \mathrm{IF}=\int Q(\mathrm{IF}) d y+C \text { i.e., } x \mathrm{e}^{\int P d y}=\int Q\left\{e^{\int P d y}\right\} d y+C$$