1. substitution rule

Why it is "
3e^u + c" and not "3(e^u + c)" ?

Thanks...

2. Hi zorspas,

$\displaystyle C$ is an arbitrary constant. If you had $\displaystyle 3(e^u+C)=3e^u+3C$ the $\displaystyle 3C$ is still constant and so this could be be written $\displaystyle 3e^u+A$ where $\displaystyle A=3C$ is a constant which is the same as $\displaystyle 3e^u+C$ as both $\displaystyle A$ and $\displaystyle C$ are constant. It's just quicker and easier to write.

3. Originally Posted by zorspas

Why it is "3e^u + c" and not "3(e^u + c)" ?

Thanks...
$\displaystyle 3 e^u + C$ is equivalent to $\displaystyle 3 (e^u + K)$.

1. Note the different symbol used for each arbitrary constant.
2. C = 3K.

4. Thanks a lot...