Help solving ODE using separation of variables

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SUMMARY

The discussion focuses on solving an ordinary differential equation (ODE) using the method of separation of variables. The user presents their solution steps, which involve integrating both sides after separating variables. They utilize Maple 10 to verify their solution and seek assistance in simplifying their result to match Maple's output. Key steps include the substitution of \( u = 1 + x^3 \) and the application of logarithmic properties to simplify the expression.

PREREQUISITES
  • Understanding of ordinary differential equations (ODEs)
  • Familiarity with integration techniques, specifically separation of variables
  • Knowledge of logarithmic properties and exponential functions
  • Experience using Maple 10 for mathematical computations
NEXT STEPS
  • Review the method of separation of variables in ODEs
  • Learn about logarithmic identities and their applications in simplification
  • Explore the use of Maple 10 for solving and verifying ODEs
  • Study the process of exponentiating logarithmic equations to simplify expressions
USEFUL FOR

Students and professionals in mathematics, particularly those studying differential equations, as well as anyone using Maple 10 for mathematical problem-solving and verification.

opticaltempest
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Hello,

Could someone please help me to simplify my solution to my ODE?

Here is the solution I get when I check it using Maple 10,

http://img524.imageshack.us/img524/415/ode2hx.jpg

Here are my steps:

[tex] \left( {1 + x^3 } \right)\frac{{dy}}{{dx}} - 3x^2 y = 0[/tex]

[tex] \left( {1 + x^3 } \right)dy = 3x^2 ydx[/tex]

[tex] \int {\frac{1}{y}} dy = \int {\frac{{3x^2 }}{{1 + x^3 }}} dx[/tex]

Let [tex]u = 1 + x^3[/tex] then [tex]\frac{{du}}{3} = x^2 dx[/tex]

[tex] \ln \left| y \right| = \frac{1}{3}\int {\frac{1}{u}} du[/tex]

[tex] \ln \left| y \right| = \frac{1}{3}\ln \left| u \right| + C[/tex]

[tex] \ln \left| y \right| = \frac{1}{3}\ln \left| {1 + x^3 } \right| + C[/tex]


How do I simplify this down to match the answer in Maple 10?
 
Last edited by a moderator:
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HINTS:

[tex]e^{\ln x} = x[/tex]

[tex]\ln x^p = p \ln x[/tex]
 
That 1/3 shouldn't be there. Once that's gone, exp both sides to get the same expression as maple.
 

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