Question

Determine the dimension of a rectangular solid(with a square base )with maximum volume if its surface area is 337.5 square centimeter.

Answer 1

maximum volume means height of solid = infinity :P

Answer 2

are u aware of the concept of derivatives to find maximum values?

Answer 3

i know how to derive but how to derive in maximum values definitely no

Answer 4

ok, volume of rect solid with square base of side x and height y is x^2y
did u get this ?

Answer 5

no

Answer 6

u know how to find volume ?

Answer 7

v=x^2 h

Answer 8

i have written same thing , just denoted height by y instead of h

Answer 9

and surface area = ??

Answer 10

sa= x^2 + 4xh

Answer 11

there will be 2 square faces, isn't it ?
so 2x^2+4xh
ok?

Answer 12

ok

Answer 13

now 2x^2+4xh=337.5 given
can u find h in terms of x from here ??

Answer 14

ahm no

Answer 15

subtract 2x^2 from both sides
then divide by 4x on both sides.
tell me what u get?