Ask your own question, for FREE!
Mathematics 11 Online
OpenStudy (tiffany_rhodes):

Need help solving the IVP: y' -y = 10te^(2t) with y(0)=1. I found the integrating factor to be u(t)=e^(-t) and the answer I got: y=10te^(2t)-10e^(2t)+11 but my answer is incorrect. I went over the problem a couple times but can't find my error. Thanks for the help!

OpenStudy (tiffany_rhodes):

*I used wolfram alpha to integrate for me because I was being lazy and didn't want to use IBP.

ganeshie8 (ganeshie8):

you forgot multiplying 11 by e^t

ganeshie8 (ganeshie8):

try y=10te^(2t)-10e^(2t)+11e^t

OpenStudy (tiffany_rhodes):

Okay. I thought you found the solution and then used the initial condition to find the constant?

ganeshie8 (ganeshie8):

yes

OpenStudy (tiffany_rhodes):

You are correct @ganeshie8

OpenStudy (tiffany_rhodes):

but why do I multiply 11 by e^t?

ganeshie8 (ganeshie8):

whats ur general solution ?

ganeshie8 (ganeshie8):

before finding the constant

OpenStudy (tiffany_rhodes):

y=10te^(2t) - 10e^(2t) +C

ganeshie8 (ganeshie8):

it should be y=10te^(2t)-10e^(2t)+Ce^t

OpenStudy (tiffany_rhodes):

Hmm, I see what your saying. When I divided the e^(-t) term over I didn't multiply the constant by e^t

ganeshie8 (ganeshie8):

show me ur work so that il be able to pinpoint the error step

OpenStudy (tiffany_rhodes):

you're*

ganeshie8 (ganeshie8):

yes.. i see you figured it out :)

OpenStudy (tiffany_rhodes):

Thanks again for your help :)

ganeshie8 (ganeshie8):

yw!

ganeshie8 (ganeshie8):

btw you may use wolfram to double check ur IVP solution http://www.wolframalpha.com/input/?i=y%27+-y+%3D+10te%5E%282t%29%2C+y%280%29%3D1

Can't find your answer? Make a FREE account and ask your own questions, OR help others and earn volunteer hours!

Join our real-time social learning platform and learn together with your friends!
Can't find your answer? Make a FREE account and ask your own questions, OR help others and earn volunteer hours!

Join our real-time social learning platform and learn together with your friends!