Differential Eq...

$$y = \sin kt$$ satisfies the differential equation $$y'' + 9y = 0$$. Then $$k=$$

The solution of the differential equation $$\dfrac{dy}{dx} = \dfrac{3y - 7x - 3}{3x - 7y + 7}$$ is 

The differential equation for all the straight lines which are at a unit distance from the origin is  

Which of the following differential equation is linear ?

Solution of the different equation, $$ydx - xdy + x{y^2}dx = 0$$ can be.

The solution of the differential equaton $$3{e^x}\tan ydx + \left( {1 - {e^x}} \right){\sec ^2}ydy = 0$$ is 

Solve $$(1+\cos x)dy=(1-\cos x)dx$$.

If $$\dfrac{dy}{dx}+y\tan x=\sin 2x$$ and $$y(0)=1$$, then $$y(\pi)=?$$

Solve:
$$ \dfrac {dy}{dx} = y \cot x$$

The D.E. obtained from $$(y - a)^2 = 4 (x - b)$$ is given by