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# Separation of Variables watch

1. Hi, I'm struggling with a separating the variables problem.

First, I make the equation 1/(y+5) dy = e^x dx
Then, I integrate to get ln(y+5)=e^x + c
Then, I raise by e^x to get y+5=e^(e^x+c)
Then simply rearrange to get y=e^(e^x+c)-5.

Have I gone wrong anywhere or can I simplify, or is it just this same test site being stupid.

Thanks
2. (Original post by Substitution)
Hi, I'm struggling with a separating the variables problem.

First, I make the equation 1/(y+5) dy = e^x dx
Then, I integrate to get ln(y+5)=e^x + c
Then, I raise by e^x to get y+5=e^(e^x+c)
Then simply rearrange to get y=e^(e^x+c)-5.

Have I gone wrong anywhere or can I simplify, or is it just this same test site being stupid.

Thanks
Looks fine, but you might want to write is as instead.
3. (Original post by Zacken)
Looks fine, but you might want to write is as instead.
That's what I thought, but the question says to use c so I left it as is.

Thanks
4. (Original post by Substitution)
That's what I thought, but the question says to use c so I left it as is.

Thanks
Maybe then? But it shouldn't make much of a difference.
5. (Original post by Zacken)
Maybe then? But it shouldn't make much of a difference.
I'll try and enter it as that tomorrow, not feeling confident about the fact were going to be using this site for our tests on monday!
6. Perhaps try also, i.e. what Zacken said but use c as it asks.

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Updated: March 19, 2016
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