Integrating factor of [tex](x+2y^3)dy/dx=y^2[/tex] is:

A. e (1/y)
B. e (-1/y)
C. y
D. -1/y

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Answer:

A) e^(1/y)

Step-by-step explanation:

Re-write the equation

[tex]\displaystyle (x+2y^3)\frac{dy}{dx}=y^2\\\\\frac{dy}{dx}=\frac{y^2}{x+2y^3}\\ \\\frac{dx}{dy}=\frac{x+2y^3}{y^2}\\ \\ \frac{dx}{dy}=\frac{x}{y^2}+2y\\ \\\frac{dx}{dy}-\frac{x}{y^2}=2y[/tex]

Since we have a first-order linear differential equation in the form of [tex]\displaystyle \frac{dx}{dy}+p(y)x=q(y)[/tex], then the integrating factor is [tex]\displaystyle IF=e^{\int {p(y)} \, dy}[/tex]. Comparing with the above form, we have [tex]\displaystyle p(x)=-\frac{1}{y^2}[/tex] and [tex]q(x)=2y[/tex]:

[tex]\displaystyle IF=e^{\int {p(y)} \, dy}\\\\IF=e^{\int {-\frac{1}{y^2} } \, dy}\\\\IF=e^\frac{1}{y}[/tex]

Thus, A is the correct answer

the answer is A

(x+2y³)dy/dx = y²
dx/dy = x/y² + 2y

Integrating factor=
IF= e^(∫−1/y^2 dy)
IF= e^(-∫1/y^2 dy)
IF= e^(-(-y^-1))
IF= e^1/y