Mathematics
4 Online
OpenStudy (anonymous):
The particular solution of the differential equation dy/ dt = y/ 4 for which y(0) = 20 is
y = 20e^−0.25t
y = 19 + e^0.25t
y = 20 e^0.25t
y = 20e^4t
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OpenStudy (anonymous):
@iGreen @Luigi0210 @hartnn @bibby
OpenStudy (xapproachesinfinity):
you can do this one by separation
OpenStudy (anonymous):
what would i get as an answer? :)
OpenStudy (xapproachesinfinity):
\[\frac{dy}{dt}=\frac{1}{4}y \Longrightarrow \frac{dy}{y}=\frac{1}{4}x\\
\int \frac{dy}{y}=1/4\int dx \Longrightarrow \ln y=\frac{x}{4}+C \]
OpenStudy (xapproachesinfinity):
take it from there...
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OpenStudy (xapproachesinfinity):
solve for y
using exp properties
OpenStudy (anonymous):
i think its C, y = 20 e^0.25t
OpenStudy (xapproachesinfinity):
idk you have to solve to figure out
OpenStudy (anonymous):
y = e^(c+x/4)
OpenStudy (anonymous):
that's what i got : )
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OpenStudy (xapproachesinfinity):
go further
use the powers rules
to get y=Ce^{x/4}
OpenStudy (xapproachesinfinity):
oh by the way that should t not x
OpenStudy (xapproachesinfinity):
just a typo in the variable we have
OpenStudy (anonymous):
y = approximately 2.7182 ^ C +0.2500x
OpenStudy (anonymous):
2.7183*
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OpenStudy (xapproachesinfinity):
what are you doing?
OpenStudy (xapproachesinfinity):
\[y=e^{t/4 +C}=e^{t/4}e^C=Ce^{t/4}\] for y(t=0)=20
we plug in t=0
\[20=Ce^0=C\Longrightarrow C=20\]
OpenStudy (xapproachesinfinity):
1/4=0.25 see what equation is good
OpenStudy (anonymous):
y = 20 e^0.25t
OpenStudy (xapproachesinfinity):
yes!
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OpenStudy (anonymous):
thank u :)
OpenStudy (anonymous):
YAY! I GOT A 100% thank u!!!!!!!!!!
OpenStudy (xapproachesinfinity):
YW