How Do You Determine p(x) and q(x) in a Second Order ODE with Given Solutions?

  • Thread starter Thread starter brad sue
  • Start date Start date
brad sue
Messages
270
Reaction score
0
Hi ,
please can I have your help?

x^2+2 and x^2-2 are fundamental set of solutions of a second order ODE. find the ODE.
form:y''+p(x) y'+ q(x) y=0.


I tried to replace the two solutions in the equation but because those solutions have exact same first and second derivatives, I found p(x)=q(x)=0 !

Can you help me to find p(x) and q(x)?
Thank you
B.
 
Physics news on Phys.org
Try again. Write out the two equations you get and solve for p and q as if they were variables and x was a constant. The two equations will be identical except for the factor in front of q (ie, y), since the two solutions only differ in their constant term (so that all their derivatives will be equal).
 
Prove $$\int\limits_0^{\sqrt2/4}\frac{1}{\sqrt{x-x^2}}\arcsin\sqrt{\frac{(x-1)\left(x-1+x\sqrt{9-16x}\right)}{1-2x}} \, \mathrm dx = \frac{\pi^2}{8}.$$ Let $$I = \int\limits_0^{\sqrt 2 / 4}\frac{1}{\sqrt{x-x^2}}\arcsin\sqrt{\frac{(x-1)\left(x-1+x\sqrt{9-16x}\right)}{1-2x}} \, \mathrm dx. \tag{1}$$ The representation integral of ##\arcsin## is $$\arcsin u = \int\limits_{0}^{1} \frac{\mathrm dt}{\sqrt{1-t^2}}, \qquad 0 \leqslant u \leqslant 1.$$ Plugging identity above into ##(1)## with ##u...
Back
Top