Answer:
x = 8,49 ft
y = 4,24 ft
Step-by-step explanation:
Let x be the longer side of rectangle and y the shorter
Area of rectangle = 36 ft² 36 = x* y ⇒ y =36/x
Perimeter of rectangle:
P = 2x + 2y for convinience we will write it as P = ( 2x + y ) + y
C(x,y) = 1 * ( 2x + y ) + 3* y
The cost equation as function of x is:
C(x) = 2x + 36/x + 108/x
C(x) = 2x + 144/x
Taking derivatives on both sides of the equation
C´(x) = 2 - 144/x²
C´(x) = 0 2 - 144/x² = 0 ⇒ 2x² -144 = 0 ⇒ x² = 72
x = 8,49 ft y = 36/8.49 y = 4,24 ft
How can we be sure that value will give us a minimun
We get second derivative
C´(x) = 2 - 144/x² ⇒C´´(x) = 2x (144)/ x⁴
so C´´(x) > 0
condition for a minimum
Answer:
4
* 7 = 28
28 - 4 = 24 = 75.36
75 square meters
Step-by-step explanation:
Answer:
13 - 4x = 1 - x
Subtract 13 from both sides.
-4x = -12 - x
Add x to both sides.
-3x = -12
Divide both sides by -3.
x=4
:)
Answer:
Step-by-step explanation:
The first part is already solved.
<u>We got the scale factor </u>
<u>Use this to find the missing side:</u>
Answer:
81
Step-by-step explanation:
