Differential equation/characteristic equation

Resa
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Any help is appreciated

1.)----Find the Character equation for the diff equation d^2y/dx^2-4dy/dx+3y=0 with initial conditions y(0)=0 and y'(0)=12 find the solution y(t)

(this is what I have gotten so far on this part) p^2+4p+3=0
then (p-1)(p-3)=0 so p1=1 and p2=3?
not really sure what to do after that
2.)----then solve the diff equation 4dy/dx+16y=80 where y(0)=6 (hint is that you have the homogenous solution in the problem above)
 
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Resa said:
Any help is appreciated

1.)----Find the Character equation for the diff equation d^2y/dx^2-4dy/dx+3y=0 with initial conditions y(0)=0 and y'(0)=12 find the solution y(t)

(this is what I have gotten so far on this part) p^2+4p+3=0
then (p-1)(p-3)=0 so p1=1 and p2=3?
not really sure what to do after that
You mean ##p^2 \color{red}{-} 4p +3##. You got the characteristic equation by assuming solutions of the form ##e^{pt}##. So what do you get for your general solution?
 
ummm is it
y(t)=Cept+C2ep2t
I really don't know...
 
LCKurtz said:
You mean ##p^2 \color{red}{-} 4p +3##. You got the characteristic equation by assuming solutions of the form ##e^{pt}##. So what do you get for your general solution?
I figured out the answers
 
Resa said:
2.)----then solve the diff equation 4dy/dx+16y=80 where y(0)=6 (hint is that you have the homogenous solution in the problem above)
Despite the hint, I don't see that this is related to question 1 at all. Have you been able to solve this problem?
 
Mark44 said:
Despite the hint, I don't see that this is related to question 1 at all. Have you been able to solve this problem?
yes
 
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...
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