Answer:
A) When using the shell method, the axis of the cylindrical shells is parallel to the axis of revolution. True.
The Shell method is a technique used to find the volume of a solid of revolution. Here, we take thin shells with axis coinciding with the axis about which the region whose volume is to be found, is revolved.
B) If a region is revolved about the y-axis, then the shell method must be used. False.
This method can be used with any axis of rotation.
C) If a region is revolved about the x-axis, then in principle it is possible to use the disk/washer method and integrate with respect to x or the shell method and integrate with respect to y. True.
The washer method uses thin disks with infinite width but the shell method uses thin concentric shells with infinite width about the axis of revolution. So, the statement is true.
Answer:
57.97 or 57 97/100 its the same answer in a different format.
Step-by-step explanation:
1st calculate the sum of the positive numbers.
Then calculate the difference
Then that's how you can get the solution
Answer:
Step-by-step explanation:
We know that we have a 9 foot long ladder resting upon a wall, with an unknown height, but the ladder is 4.5 feet away from the wall.
This can be represented as a triangle, where x is the unknown side.
|\
| \
x | \ 9
| \
| \
|_____\
4.5
We can use The Pythagorean Theorem to find the value of x. The theorem states that , where a and b are the lengths of the legs and c is the length of the hypotenuse.
However, we already know the hypotenuse and one leg. Therefore we can substitute inside the equation to find the missing value.
Hope this helped!
Longer leg = x + 4
Shorter leg = x
Hypotenuse = x + 8
Using Pythagorean Theorem:
a^2 + b^2 = c^2
(x + 4)^2 + x^2 = (x + 8)^2
x^2 + 8x + 16 + x^2 = x^2 + 16x + 64
2x^2 + 8x + 16 = x^2 + 16x + 64
2x^2 +8x = x^2 + 16x + 48
2x^2 - 8x = x^2 + 48
x^2 - 8x = 48
x^2 - 8x - 48 = 0
You can complete the square from here or use the quadratic formula.
Completing the square:
x^2 - 8x = 48
x^2 - 8x + (-8/2)^2 = 48 + (-8/2)^2
x^2 - 8x + 16 = 48 + 16
(x - 4)(x - 4) = 64 or (x - 4)^2 = 64
x - 4 = +√64 OR x - 4 = -√64
x - 4 = +8 OR x - 4 = -8
x = 12 OR x = -4
However, you can't use negative 4 as a length because your length needs to be a positive.
So x will be 12.
Shorter leg: 12
Longer leg: 12 + 4
Hypotenuse: 12 + 8
Complete the math in the brackets (4a + 1)
Multiple each term in the brackets by 4a
4a (8a - 4a + 1)
4a (4a + 1)
16a^2 + 4a