How prove the maximum of 2 functions

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Discussion Overview

The discussion revolves around the mathematical derivation of the maximum of two functions, specifically the expression M(x) = ½ [ ( f + g ) + | f – g | ]. Participants seek to understand how this formula is derived from first principles and whether it can be proven for both numbers and functions.

Discussion Character

  • Exploratory, Technical explanation, Homework-related

Main Points Raised

  • One participant presents the formula for the maximum of two functions and requests a proof or derivation.
  • Another participant suggests proving the formula for numbers first, specifically the case max(x, y) = ((x + y) + |x - y|) / 2, before extending it to functions.
  • A later reply acknowledges that the formula applies to both numbers and functions but seeks clarification on its origin and derivation from first principles.
  • One participant provides a link to a previous thread that may contain relevant information.

Areas of Agreement / Disagreement

Participants generally agree on the validity of the formula for both numbers and functions, but the discussion remains unresolved regarding the derivation and first principles behind the equation.

Contextual Notes

There is a lack of detailed exploration into the assumptions or definitions that underpin the derivation of the maximum function, and the discussion does not resolve how the formula is created from first principles.

lmamaths
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Hi,

The maximum of 2 functions, namely f(x) and g(x) is defined as…

M(x) = ½ [ ( f + g ) + | f – g | ]

Can someone show me how this is proved out
or derived please?

Many Thx! :smile:
 
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(a) Can you prove it for numbers?
I.E. max(x, y) = ((x + y) + |x - y|) / 2

(b) Once you've done that, can you then prove it for functions?
 
How to prove the maximum of 2 functions

Thx Hurkyl,

Yes you are correct it works for both numbers as well as functions. But what I need to know is where or how did this equation come about – that is, do you know how it was created from First Principles – and please tell me how this is done if you know!

Many thx!
 

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