High School

A box measures 15 x 20 inches. Squares of the same size, with side length x, are cut out from each corner of the box. Write an expression for the new length of the box.

Answer :

Answer:

İt is solved by using derivative


The edges of box are 20–2x,15–2x and x


Volume=(20–2x).(15–2x).x


İf you take derivative and then find the roots of derivative we obtain exstramum points that means these values make volume maximum or minimum


But


Answer is not rational

Answer:

A = 300-x^2 for area

A = 20L * 15 -x^2 for area

20L - x^2 = 300 - x^2 /15 -x^2 could also work to find length .

SIMPLIFIED

L - x = 300/20 - ( x^2 )/ 15 - x

Step-by-step explanation:

Length = L = 20 inches.

Area of one side = A = 15 X 20 = 300 cm^2

= 300 - x^2

This means the missing corner square is also squared

Simplifies to sqrt 300 - x

but as length was asked 20L * 15 -x^2

we know one side may be 15x 15

and if one side is 15 x 20

then instead of 15 x 15 it may be 15 x 20

eitherway we are looking at one side representing area of one side of the box. 300-x is our answer.