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Differential equation form watch

1. Q. By eliminating the arbitrary constant A find the first order differential equation that is equivalent to;

My answer;
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2. Answer

3. d/dx(constant) = 0
4. (Original post by ckfeister)
Q. By eliminating the arbitrary constant A find the first order differential equation that is equivalent to;

My answer;
You forgot to differentiate the constant A in the second line!
5. (Original post by NotNotBatman)
d/dx(constant) = 0
(Original post by SlashaRussia)
You forgot to differentiate the constant A in the second line!
dy/dx = y/x (can't use latex as the / (oppose side one) is broken for some annoying reason)

(1/y) dy = (1/x) dx
ln(y) = ln(x) + c
y = x + e^c
:. y = x + A

The answer says it is
y = Ax
???
6. (Original post by ckfeister)
ln(y) = ln(x) + c
y = x + e^c
This step is wrong.
7. (Original post by RDKGames)
This step is wrong.
Ive bee trying to see where for a few hours with other questions having the same issue, isn't that anti-log? I'm going what I know from textbook only as I'm self-studying.
8. (Original post by ckfeister)
dy/dx = y/x (can't use latex as the / (oppose side one) is broken for some annoying reason)

(1/y) dy = (1/x) dx
ln(y) = ln(x) + c
y = x + e^c
:. y = x + A

The answer says it is
y = Ax
???
9. (Original post by NotNotBatman)
Well thats new...
So
ln[y] = ln[x] + c
y = e^(ln[x] + c)
y = Ax (as e^ln[x] = x)
10. (Original post by ckfeister)
Well thats new...
So
ln[y] = ln[x] + c
y = e^(ln[x] + c)
y = Ax (as e^ln[x] = x)
Bit worrying if that's new!

is something Y10s work with.
11. (Original post by RDKGames)
Bit worrying if that's new!

is something Y10s work with.
In year 10 I got E/Fs which was normal in my school as it is one of the worst as well as the one of the most disadvantaged area in South East England...
12. (Original post by ckfeister)
Well thats new...
So
ln[y] = ln[x] + c
y = e^(ln[x] + c)
y = Ax (as e^ln[x] = x)
This is a rule you should know, if it's new, go over any other little bits of algebra, to make sure that you can do these type of questions.

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