Mathematics
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OpenStudy (anonymous):
Solve the equation for y in terms of x:
3y + 2y^2 = -e^(-x) - e^(x) + 7
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OpenStudy (dinamix):
its not differential equation ?
OpenStudy (anonymous):
Ill post the entire question and maybe that'll help
OpenStudy (anonymous):
Find the solution to the initial value problem in explicit form
\[y' = \frac{e^{-x} - e^{x}}{3 + 4y}\]
OpenStudy (anonymous):
y(0) = 1
OpenStudy (anonymous):
@dan815 ?
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OpenStudy (freckles):
y'*y doesn't equal y^2
OpenStudy (freckles):
\[(3+4y) dy=(e^{-x}-e^{x} )dx\]
equation is seperable
integrate both sides
OpenStudy (freckles):
oh wait are you saying you think you found the solution to that?
OpenStudy (anonymous):
yes i believe so and now i need it in explicit form
OpenStudy (anonymous):
I believe i have found the correct value for the constant c given the initial value as well
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OpenStudy (freckles):
your solution is correct
OpenStudy (freckles):
don't believe you can find explicit form
OpenStudy (anonymous):
the answer in the back of the book has done it some how.
OpenStudy (freckles):
hmmm
well you have a quadratic in terms of y
OpenStudy (freckles):
\[2y^2-3y+e^{-x}+e^{x}-7=0 \\ y=\frac{-(-3) \pm \sqrt{(-3)^2-4(2)(e^{-x}+e^{x}-7)}}{2(2)}\]
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OpenStudy (freckles):
though the implicit form looks much better to me
OpenStudy (anonymous):
that looks like the answer, how'd you do that?!
OpenStudy (freckles):
it is a quadratic in terms of y
OpenStudy (freckles):
all i did was use the quadratic formula
OpenStudy (freckles):
a=2
b=-3
c=e^(-x)+e^x-7
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OpenStudy (anonymous):
ohhhhh
OpenStudy (anonymous):
i gotcha now
OpenStudy (anonymous):
Thank you!!!!!!
OpenStudy (freckles):
np