A closed box is constructed of 4200cm2 of cardboard. The box is a cuboid, with height hcm and square base of side xcm . What is the value of x which maximises the volume of the box? Give your answer in cm correct to 3 significant figures. [Answer format: 00.0 cm]

x is 10

Step-by-step explanation:

Given that:

<=> 2 + 4xh = 4200 cm2

<=> 4xh = 4200 - 2  

<=> h = (4200 - 2  )/4x

V =  h

<=> V =  (4200 - 2  )/4x

<=> V = (4200x - 2 )/4

dV/dx = (4200 - 6 )/4

Set dV/dx = 0, we have:

4200 - 6 =0

<=>  = 700

<=> x = 10

d²V/dx² =  -12x/4

It is negative so the volume is maximum.

So x is 10

yeah and the opposite of cheating is studying ( you should try it some time)

step-by-step explanation:

y-y1=4(x-x1)

step-by-step explanation:

this is point-slope form since you only have 4 as the slope it goes in place of m

hope this : )