Posted by dt on .
the sum of two nonnegative numbers is 20. find the number if
a. the sum of their squares is as large as possible; as small as possible
b. oen number plus the square root of th eother is as large as possible; as samll as possible

12th Calculus 
Reiny,
a) let S be the sum of their squares
then
S = x^2 + (20x)^2
take dS/dx, set that equal to zero and solve
b) S = (20x) + √x
same thing, find dS/dx, set equal to zero and solve