- #1

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## Homework Statement

Hi,

I am looking at this question:

With this (part of ) solution:

## Homework Equations

## The Attempt at a Solution

I follow up to the last line-

I do not understand here how we have simply taken the ##1/t^{\alpha m + \alpha}## outside of the derivative ##\frac{\partial}{\partial y} ## since ##y=y(r,t^{\beta}) ## i.e. ##t## and ##y## are not independent variables.... ##\frac{\partial}{\partial t}= \frac{\partial y}{\partial t^{\beta}}\frac{\partial t^{\beta}}{\partial t}##

Many thanks in advance