First order linear differential Equation

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SUMMARY

The discussion focuses on solving the first order linear differential equation given by $$(x^2+1)y'-2xy=x^2+1$$ with the initial condition $$y(1)=\frac{\pi}{2}$$. The user initially attempts to simplify the equation by dividing through by $$x^2+1$$, leading to the equation $$y'-\frac{2xy}{x^2+1}=1$$. The correct integrating factor is derived as $$e^{-\int\frac{2x}{x^2+1}dx}= \frac{1}{x^2+1}$$, which allows the user to proceed with solving the differential equation. The user expresses gratitude for the clarification on logarithmic properties that aided in the simplification process.

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  • Understanding of first order linear differential equations
  • Familiarity with integrating factors in differential equations
  • Knowledge of logarithmic and exponential functions
  • Basic calculus skills for integration
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  • Study the method of integrating factors for linear differential equations
  • Learn about the properties of logarithms and exponentials
  • Practice solving first order linear differential equations with varying initial conditions
  • Explore applications of differential equations in real-world scenarios
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Students and professionals in mathematics, particularly those studying differential equations, as well as educators looking for examples of solving first order linear differential equations.

Petrus
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Hello MHB,
$$(x^2+1)y'-2xy=x^2+1$$ if $$y(1)=\frac{\pi}{2}$$What I have done:
Divide evrything by $$x^2+1$$ and we got
$$y'-\frac{2xy}{x^2+1}=1$$
we got the integer factor as $$e^{^-\int\frac{2x}{x^2+1}}= e^{-ln(x^2+1)}$$
Now I get
$$(e^{-ln(x^2+1)}y)'=e^{-ln(x^2+1)}$$
and this lead me to something wrong, I am doing something wrong or?

Regards,
$$|\pi\rangle$$
 
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Try simplifying the expression first , remember logarithm and exponential are (inverse) ...
 
ZaidAlyafey said:
Try simplifying the expression first , remember logarithm and exponential are (inverse) ...
that means if I got right
$$e^{-ln(x^2+1)}=-x^2-1$$?

Regards,
$$|\pi\rangle$$
 
No , remember the rules of logarithm $$\log x^n = n\log x $$ .
 
ZaidAlyafey said:
No , remember the rules of logarithm $$\log x^n = n\log x $$ .
Ahhh I see now! $$e^{-ln(x^2+1)}=e^{ln((x^2+1)^{-1})}= \frac{1}{x^2+1}$$
Thanks a lot Zaid! I should be able to continue!:) Thanks for fast responed and taking your time!

Regards,
$$|\pi\rangle$$
 

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