i'm going through some homework, but there is one thing i don't understand. Our task is to explain the following calculation:
Given: $h(x) = \ln(x^4)$
I.
$ \begin{align} h(x) = t(x) &\Rightarrow \ln(x^4) = mx = 4 \\ &\Rightarrow x^4 = e^4 \\ &\Rightarrow x = e \quad \textrm{or}\quad x = -e \end{align} $
I am confused about the line: $\Rightarrow \ln(x^4) = mx = 4$.
II.
\begin{align} h'(x) = m &\Rightarrow 4/x = m \\ &\Rightarrow x = 4/m \\ &\Rightarrow t(x) = \frac{4x}{e} \end{align}
I just can't figure out what hes doing here :/