I have: $\ln(ax + b)^4$
After calculating ($u'$/$u$) I get:
$4/(ax+b)$ but the solution is $4a/(ax+b)$
What am I doing wrong? Thanks!
PS: $a$ and $b$ are $\mathbb R^+ $
I have: $\ln(ax + b)^4$
After calculating ($u'$/$u$) I get:
$4/(ax+b)$ but the solution is $4a/(ax+b)$
What am I doing wrong? Thanks!
PS: $a$ and $b$ are $\mathbb R^+ $
You need to apply the chain rule, using $\frac{d}{dx}(ax+b)=a$. (That is your missing factor of $a$.) I can't tell whether you did so, but you can also simplify the first expression to $4\log(ax+b)$.