A company makes computer chips from square wafers of silicon. It wants to keep the side length of a wafer very close to 20 mm and it wants to know how the area A(x) of a wafer changes when the side length x changes. Find A'(20).

The answer is  40 mm^2 per mm

Step-by-step explanation:

The area of  a square with side length is  x

and

A(x) = ()

The Derivative of the area is the rate of change of the area.

so

(x) = 2x

and we have to find (20)

so  we put x = 20 in the derivative of the area we get

(20) = 2(20)

(20) = 40 per mm

that is we need

A'(20) = 40 per mm.

f(x) = - 2/3x + 5; f(5/2)

substitute 5/2 in for x:

f(5/2) = -2/3(5/2) + 5

simplify the right side:

f(5/2) = -5/3 + 5

f(5/2) = 10/3

answer:

f(5/2) = 10/3

i hope this you!