Max/min questions (1 Viewer)

[enigma_1]

1) Show that a rectangle with fixed perimeter has its shortest diagonal when it is a square.

2) Show that a closed cylindrical can of fixed volume will have minimum surface area when its height is equal to its length to its diameter.


How do you do those questions?
Thanks

 

[braintic]

1) Show that a rectangle with fixed perimeter has its shortest distance when it is a square.

2) Show that a closed cylindrical can of fixed volume will have minimum surface area when its height is equal to its length to its diameter.


How do you do those questions?
Thanks

A solution to your second question is attached:
View attachment Max-Min.pdf

The first question is meaningless. I don't know what this distance is that we are supposed to minimise.

 

[enigma_1]

A solution to your second question is attached:
View attachment 29389

The first question is meaningless. I don't know what this distance is that we are supposed to minimise.

Thank you soo much man for the effort you went up to!! Repped

Sorry I mistyped the first question. I have fixed it up now - it was meant to be 'diagonal'.

 

[braintic]

Solution to the first question here:

View attachment Max-Min 2.pdf