contestada

consider a closed rectangular box with a square base with side length x and height y. find the surface area, S(x,y). if the surface area is 24 square feet when x=2 and y=6 find dy/dx
find S(x,y) =

Respuesta :

S(x,y) = 4xy + 2x^2

32 = 4xy + 2x^2

4xy = 32-2x^2

y = 32/4x - (1/2)x

y' = dy/dx = -8/x^2 - 1/2 = -8/4 - 1/2 = -2 - 1/2 = -5/2

y'= -5/2

or

32 = 4xy + 2x^2

0 = 4xy' + 4y + 4x = 4(2)y' + 4(3) + 4(2) = 8y' +20

8y'=-20

y'= -20/8 = -5/2

dy/dx = -5/2

Otras preguntas