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VCE Stuff => VCE Mathematics => VCE Mathematics/Science/Technology => VCE Subjects + Help => VCE Mathematical Methods CAS => Topic started by: ally1784 on February 27, 2021, 11:48:58 pm

Title: Guys I also need help for this too
Post by: ally1784 on February 27, 2021, 11:48:58 pm

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Title: Re: Guys I also need help for this too
Post by: fun_jirachi on February 27, 2021, 11:56:02 pm

Q1 - you're given that xy = 400 and the perimeter is denoted by 2(x+y). You can make a substitution for either variable that will result in a quadratic equation, for which you can find a perimeter (on inspection or calculus or whatever other method you choose).

Q2 - similar idea, only that this time xy = 100 and x+y is unknown.

Curiously, the minimum perimeter is where x = y ie. a square in Q1, and this will always be the case for any area vs. perimeter question of this sort. It might help to think about why this is the case.


Hope this helps :)