a metal wire 36cm long is bent to form a rectangle find its dimensions when its area is maximum - Maths - Application of Derivatives

Question

a metal wire 36cm long is bent to form a rectangle find its
dimensions when its area is maximum

Rafikan · Answer

Let length = x cm
Let b = y cm
parameter = 2( x+y) cm
36 = 2 (x+y)
18 = x+y
y = 18 - x

area = xy
=x(18 -x)
a' =18x- x2
=18 - 2x
for max area a' =0
0 = 18 - 2x

x= 9 cm &
y= 36 - x
y = 27 cm

a metal wire 36cm long is bent to form a rectangle.find its dimensions when its area is maximum.