Arectangular storage container with an open top is to have a volume of 10m3. thelength of its base is twice the width. material for the base costs $ 10 per square meter. material for the sides costs $ 6 per square meter. find the cost of the material for thecheapest such container.

$163.54

Step-by-step explanation:

Volume of rectangular container = 10m^3

Length = 2(width)

Material for the base cost $10 per square meter

Material for the side cost $6 per square meter

Volume = L*B*H

L= 2W

V = (2W).W. H

10 = 2W^2.H

H = 10 /2W^2

H = 5/W^2

Let C(w) = cost function

C(w) = 10(L.W) + 6(2.L.H + 2.W.H)

= 10(2W.W) + 6(2.2W.H + 2.W.H)

= 10(2W^2) + 6(4W.H + 2.W.H)

= 10(2W^2) + 6(4W*5/W^2 + 2.W*5/W^2)

= 20W^2 + 6(20/W + 10/W)

= 20W^2 + 6((10+20)/W)

= 20W^2 + 6(30/W)

C(w) = 20W^2 + 180/W

To find the minimum value, differentiate C with respect to w

C'(w) = 40W - 180/W^2

Put C'(w) = 0

0 = 40W - 180/W^2

40W = 180/W^2

40W^3 = 180

W^3 = 180/40

W^3 = 4.5

W = cube rt(4.5)

W = 1.65m

C = 20(1.65)^2 + 180/1.65

C = 54.45 + 109.09

C= $163.54

Minimum cost = $163.54

b. an equilateral triangle inscribed in a circle

step-by-step explanation:

we are given the figure of two circles having a triangle inside.

now, we know that,

"when a figure is lying inside an another figure, then the outside figure is known as circumscribed figure and the figure lying inside is referred to as the inscribed figure".

as we see that, the circles are containing the triangle completely.

thus, the circles are the circumscribed figures and the triangle is the inscribed figure.

hence, we get, 'an equilateral triangle is inscribed in a circle'.

the answer will be the last one