Find the domain for the particular solution to the differential equation dy dx equals the quotient of 3 times y and x , with initial condition y(1) = 1.

Respuesta :

For this case we have the following difference equation:
 [tex] dy / dx = 3xy [/tex]
 Applying separable variables we have:
 [tex] dy / y = 3xdx [/tex]
 Integrating both sides we have:
 [tex] \int\ ({1/y}) \, dy = \int\ {3x} \, dx [/tex]
 [tex] ln (y) = (3/2) x ^ 2 + C [/tex]
 applying exponential to both sides:
 [tex] exp (ln (y)) = exp ((3/2) x ^ 2 + C) y = C * exp ((3/2) x ^ 2)[/tex]
 For y (1) = 1 we have:
 [tex]C = 1 / (exp ((3/2) * 1 ^ 2)) C = 0.2[/tex]
 Thus, the particular solution is:
 [tex] y = 0.2 * exp ((3/2) x ^ 2) [/tex]
 Whose domain is all real.
 Answer:
 y = 0.2 * exp ((3/2) x ^ 2)
 Domain: all real numbers