A curve passes through the point (0,-2) and at any point (x, y) of the curve, the product of the slope of its tangent and y-coordinate of the point is equal to the x-coordinate of the point. Find the equation of the curve.
A curve passes through the point (0,-2) and at any point (x, y) of the curve, the product of the slope of its tangent and y-coordinate of the point is equal to the x-coordinate of the point. Find the equation of the curve.

Solution:

It is given that product of slope of tangent and y coordinate equals the x-coordinate i.e., y \frac{d y}{d x}=x
We have, y d y=x d x
\begin{array}{l} \Rightarrow \int y d y=\int x d x \\ \Rightarrow \frac{y^{2}}{2}=\frac{x^{2}}{2}+c \end{array}
For the curve passes through (0,-2), we get c=2
Hence, the required particular solution is:-
\therefore y^{2}=x^{2}+4