(1/4)=0.25
0.25*0.25*0.25=0.015625
Answer:
23. x = 4; DE = 44
24. x = 25; DS = 28
Step-by-step explanation:
23. Point S is the midpoint of DE, so ...
DS = SE
3x +10 = 6x -2
12 = 3x . . . . . . . . . add 2-3x
4 = x . . . . . . . . . . . divide by 3
Then DS has length ...
DS = 3x +10 = 12 +10 = 22
and DE is twice that length, so ...
DE = 44
__
24. DS is half the length of DE, so is ...
DS = DE/2 = 56/2
DS = 28
Then x can be found from ...
DS = x +3
28 -3 = x = 25 . . . . . substitute value for DS
_____
<em>Comment on problem 24</em>
Sometimes it is easier to work parts of a problem out of sequence. Here, finding DS first makes finding x easier.
Answer:
Imagine we are to express [
a
,
b
] in set notation
A
=
[
a
,
b
]
, then A
=
{
x ∈ R / a
≤
x
≤
b
}
In this notation we define the characteristics of all x belonging to this set A
....x must be greater or equal to a and simultaneously smaller or equal to b...
Interval notation is other way to say the same but assuming that means the extreme a is IN the interval and means extreme a is not.
(Простите, пожалуйста, мой английский. Русский не мой родной язык. Надеюсь, у вас есть способ перевести это решение. Если нет, возможно, прилагаемое изображение объяснит достаточно.)
Use the shell method. Each shell has a height of 3 - 3/4 <em>y</em> ², radius <em>y</em>, and thickness ∆<em>y</em>, thus contributing an area of 2<em>π</em> <em>y</em> (3 - 3/4 <em>y</em> ²). The total volume of the solid is going to be the sum of infinitely many such shells with 0 ≤ <em>y</em> ≤ 2, thus given by the integral

Or use the disk method. (In the attachment, assume the height is very small.) Each disk has a radius of √(4/3 <em>x</em>), thus contributing an area of <em>π</em> (√(4/3 <em>x</em>))² = 4<em>π</em>/3 <em>x</em>. The total volume of the solid is the sum of infinitely many such disks with 0 ≤ <em>x</em> ≤ 3, or by the integral

Using either method, the volume is 6<em>π</em> ≈ 18,85. I do not know why your textbook gives a solution of 90,43. Perhaps I've misunderstood what it is you're supposed to calculate? On the other hand, textbooks are known to have typographical errors from time to time...