Help please
Differential Equations. \[\frac{ dp }{ dt }=2\sqrt{pt}\] with y(0) = −1 as the initial value.
Here is my work. I messed up somewhere. Could someone please check my work?
@random231
You can quickly check wolfram to make sure you have the right 'final' answer.
What happened to the 2?
Where did the two go?
Oh Sorry. One sec...
\[ \frac{dp}{dt} = 2\sqrt{pt} \\ \, \\ \frac{dp}{dt} = 2\sqrt{p}\sqrt{t} \\ \, \\ \frac{1}{\sqrt p} \frac{dp}{dt} = 2\sqrt{t} \\ \, \\ \int p^{-1/2}~ \frac{dp}{dt} ~dt= 2\int t^{1/2}~dt \\ \, \\ \int p^{-1/2}~ dp= 2\int t^{1/2}~dt \\ \, \\ \frac{ p^{1/2}}{1/2} =2 \frac{t^{3/2}}{3/2} + C \\ \, \\ 2\sqrt p =2 \frac 2 3 t^{3/2}+ C \\ \, \\ \sqrt p = \frac 2 3 t^{3/2}+ C^{*} \\ \, \\ p = \left( \frac 2 3 t^{3/2}+ C \right)^2 \]
you can leave it in the square root form to find C
In your directions you have a mixture of variables. p , t, and y.
Differential Equations. \[\frac{ dp }{ dt }=2\sqrt{pt}\] with y(0) = −1 as the initial value. <--- did you mean p(0) = -1 ?
Then would... \[c = \frac{ 3\sqrt{5}-2 }{ 3 }\]
Yes i did, sorry
@owen3 Oh wait. no i didnt. I looked at at a different problem...
p(1)=5
I was going to say, this gives you a non real solution.
Haha, sorry
\[ \sqrt p = \frac 2 3 t^{3/2}+ C^{*} \\ \, \\ \sqrt 5 = \frac 2 3 1^{3/2}+ C^{} \\ \, \\ C = \sqrt 5 - \frac 2 3 \]
\[ p = \left( \frac 2 3 t^{3/2}+ \sqrt 5 - \frac 2 3 \right)^2 \]
Is it possible they meant \[ \frac{dP}{dt} = 2 \sqrt{ P(t)} \] also that should be capital \[P \]
oh okay. haha... thanks.
Yes.
Could you check something for me real quick though?
I watched this video tutorial on a problem of mine, but it wont accept the answer? Did i happen to input it incorrectly?
@owen3 See, i got it right :)
You want to solve $$ \frac{dy}{dt} = ky( 1 - y) $$
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