(a) Solve the following differential equation : dydx=ex−y+x2e−y\frac{dy}{dx} = e^{x - y} + x^2 e^{-y}. OR (b) Solve the following differential equation : (x2−y2)dx+2xydy=0(x^2 - y^2) dx + 2xy dy = 0.

Answer: ey=ex+x33+Ce^y = e^x + \frac{x^3}{3} + C

Step-by-step solution

Step 1: Rewrite the differential equation

The given differential equation is dydx=ex−y+x2e−y\frac{dy}{dx} = e^{x - y} + x^2 e^{-y}. We can rewrite ex−ye^{x-y} as exe−ye^x e^{-y}. This allows us to factor out e−ye^{-y} from the right-hand side.

Step 2: Separate the variables

Factor out e−ye^{-y} from the right-hand side. Then, separate the variables by multiplying both sides by eye^y and dxdx. This puts all terms involving yy on one side and all terms involving xx on the other, making it a separable differential equation.

Step 3: Integrate both sides

Now that the variables are separated, integrate both sides of the equation. The integral of eye^y with respect to yy is eye^y, and the integral of ex+x2e^x + x^2 with respect to xx is ex+x33e^x + \frac{x^3}{3}. Remember to add the constant of integration.

Step 4: Solve for y

After integrating, we get ey=ex+x33+Ce^y = e^x + \frac{x^3}{3} + C, where CC is the constant of integration. This is the general solution to the differential equation.

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