<span>12.3
Volume function: v(x) = ((18-x)(x-1)^2)/(4pi)
Since the perimeter of the piece of sheet metal is 36, the height of the tube created will be 36/2 - x = 18-x.
The volume of the tube will be the area of the cross section multiplied by the height. The area of the cross section will be pi r^2 and r will be (x-1)/(2pi). So the volume of the tube is
v(x) = (18-x)pi((x-1)/(2pi))^2
v(x) = (18-x)pi((x-1)^2/(4pi^2))
v(x) = ((18-x)(x-1)^2)/(4pi)
The maximum volume will happen when the value of the first derivative is zero. So calculate the first derivative:
v'(x) = (x-1)(3x - 37) / (4pi)
Convert to quadratic equation.
(3x^2 - 40x + 37)/(4pi) = 0
3/(4pi)x^2 - (10/pi)x + 37/(4pi) = 0
Now calculate the roots using the quadratic formula with a = 3/(4pi), b = -10/pi, and c = 37/(4pi)
The roots occur at x = 1 and x = 12 1/3. There are the points where the slope of the volume equation is zero. The root of 1 happens just as the volume of the tube is 0. So the root of 12 1/3 is the value you want where the volume of the tube is maximized. So the answer to the nearest tenth is 12.3</span>
Its 1.4 just use a calculator
Answer:
For number 7 it is 6x*4
For number 8 it is 3(6+4)
Have a great day :)
<h3>Isolate y on both equations then equate </h3>
- x²-3x+2y=-4
- 2y=-x²+3x-4
- y=-x²/2+3/2x-2
Now you can equate it with second one to get x
(2^8 x 3^-5 x 6^0) x [(3^-2/2^3) x 2^28] = x
(256 x .004 x 1) x [(.111/8) x 268,435,456] = x
(1.024 x 1) x .(0138 x 268,435,456) = x
1.024 x (.0138 x 268,435,456) = x
1.024 x 3,704,409.2928 = x
3,793,315.1158272 = x
Correct me if I am wrong. :)
