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Verified Answer :

(1−2x^2−2y)y′=4x^3+4xy

(1−2x^2−2y)dy=(4x^3+4xy)dx

(4x^3+4xy)dx+(−1+2x^2+2y)dy=0

f(x,y)=C;df(x,y)=∂f/∂x(dx)+∂f/∂y(dy)=0

∂f /∂x=4x^3+4xy⇒f(x,y)=x^4+2x^2y+g(y)

∂f/∂y=−1+2x^2+2y=2x^2+∂g/∂y⇒∂g/∂y=2y−1

g(y)=y^2−y⇒f(x,y)=x^4+2x^2y+y^2−y=(x^2+y)2−y=C

Answer:

\(u=-x^4-2x^2y+y-y^2\)

Step-by-step explanation:

We are given that

\((1-2x^2-2y)\frac{dy}{dx}=4x^3+4xy\)

We have to solve the given differential equation

\((1-2x^2-2y)dy=(4x^3+4xy)dx\)

\((1-2x^2-2y)dy-(4x^3+4xy)dx=0\)

Compare with \(Mdx+ndy=0\)

Then, we get \(M=-(4x^3+4xy),N=(1-2x^2-2y)\)

Exact differential equation

\(M_y=N_x\)

\(M_y=-4x\)

\(N_x=-4x\)

\(M_y=N_x\)

Hence, the differential equation is an exact differential equation.

Solution of exact differential is given by

\(u=\int M(x,y)dx+K(y)\) where K(y) is a function of y.

\(u=\int -(4x^3+4xy) dx+k(y)\) y treated as constant

\(u=-x^4-2x^2y+k(y)\)

\(u_y=N\)

\(-2x^2+k'(y)=1-2x^2-2y\)

\(K'(y)=1-2y\)

\(k(y)=y-y^2\)

Substitute the value then we get

Then, \(u=-x^4-2x^2y+y-y^2\)