I have the following equation:
$$ y = q_0\left(1+\frac{bx}{a}\right)^{-\dfrac 1b}$$
where $q_0$, $a$ and $b$ are constants. I am trying to get the first derivative with respect to $x$.
Here's what I have so far.
$$ \frac{dy}{dx} = \frac{-q_0}{a}x^\frac{-b-1}{b} $$
But I don't think that this is correct.
I think you had a good thinking (at least for the general method of derivation), however, it seems to me that you simplified the term a bit quickly:
$$ 1+\frac{b x}{a} $$
It can't be deleted as you did. So the result would be more like: $$ -\frac{q_0 \left(\frac{b x}{a}+1\right)^{-\frac{b+1}{b}}}{a} $$
Sincerely,
La Jargille
