# Tag Info

Let us assume all these functions exist and are differentiable. Furthermore let us denote the inverse of the function $\overline u^1(x_1)$ by $x_1\left(\overline u^1\right)$. Note that for any invertible function $f$ we have $$\left.\frac{\text{d} f(x)}{\text{d} x}\right|_{x=x_0} = \frac{1}{\left.\frac{\text{d} f^{-1}(y)}{\text{d} y}\right|_{y=f(x_0)}}.$$...