Question

Find two positive numbers whose sum is 100 and the sum of whose squares is a minimum.

Answer 1

Is it just me or is this problem pretty complex?

Answer 2

this is what all of my problems are like... FML

Answer 3

I don't understand squares is a minimum... hmmm

Answer 4

x+y=100
x^2+y^2= something
x^2 + (100-x)^2 = something
differentiate
set equal to zero

Answer 5

i know how to do the problem now.. i just feel like these problems are really complex

Answer 6

x+y=100 ----> y=100-x
k=x^2+y^2
k=x^2+(100-x)^2
k=x^2+10,000-200x+x^2
k=2x^2-200x+10,000
u can use derivative like @Algebraic! said

Answer 7

A rancher with 750ft of fencing wants to enclose a rectangular area and then divide it into four pens with fencing parallel to one side of the rectangle.
a. Find a function that models the total area of the four pens.
b. Find the largest possible total area of the four pens.

Answer 8

the 2nd problem ?

Answer 9

ya......

Answer 10

from the figure we can maka a models the total area of the four pens :
6x+4y=750 or
3x+2y=375
2y=375-3x
y=(375-3x)/2 ...(1)
the total area (A) = 4xy ....(2)
subt (1) to (2) we get a function :
A=4x(375-3x)/2
A=-6x^2+750x