Find a general solution of the following differential equation
dy/dx - 5y = (xe^-2x)*y^-2
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Expert's answer
2022-03-15T17:26:31-0400
Solve Bernoulli’s equation dxdy(x)−5y(x)=y(x)2e−2xx:Multiply both sides by 3y(x)2:3dxdy(x)y(x)2−15y(x)3=3e−2xxLet v(x)=y(x)3, which gives dxdv(x)=3y(x)2dxdy(x):dxdv(x)−15v(x)=3e−2xx Let μ(x)=e∫−15dx=e−15x. Multiply both sides by μ(x):e−15xdxdv(x)−(15e−15x)v(x)=3e−17xx Substitute −15e−15x=dxd(e−15x):e−15xdxdv(x)+dxd(e−15x)v(x)=3e−17xx Apply the reverse product rule fdxdg+gdxdf=dxd(fg) to the left-hand side: dxd(e−15xv(x))=3e−17xx
Evaluate the integrals:e−15xv(x)=3e−17x(−17x−2891)+c1, where c1 is an arbitrary constant. Divide both sides by μ(x)=e−15x:v(x)=2891e−2x(−51x+289c1e17x−3) Solve for y(x) in v(x)=y(x)3:y(x)=172/3e−(2x)/33−51x+289c1e17x−3 or y(x)=−172/33−1e−(2x)/33−51x+289c1e17x−3 or y(x)=172/3(−1)2/3e−(2x)/33−51x+289c1e17x−3 Simplifying the arbitrary constants we have:y(x)=172/3e−(2x)/33−51x+c1e17x−3 or y(x)=−172/33−1e−(2x)/33−51x+c1e17x−3 or y(x)=172/3(−1)2/3e−(2x)/33−51x+c1e17x−3
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