The two parabolas intersect for

and so the base of each solid is the set

The side length of each cross section that coincides with B is equal to the vertical distance between the two parabolas,
. But since -2 ≤ x ≤ 2, this reduces to
.
a. Square cross sections will contribute a volume of

where ∆x is the thickness of the section. Then the volume would be

where we take advantage of symmetry in the first line.
b. For a semicircle, the side length we found earlier corresponds to diameter. Each semicircular cross section will contribute a volume of

We end up with the same integral as before except for the leading constant:

Using the result of part (a), the volume is

c. An equilateral triangle with side length s has area √3/4 s², hence the volume of a given section is

and using the result of part (a) again, the volume is

Answer:
a i think give me brainliest. good day.
Step-by-step explanation:
Answer:
The required probability is 0.55404.
Step-by-step explanation:
Consider the provided information.
The number of typographical errors on a page of the first booklet is a Poisson random variable with mean 0.2. The number of typographical errors on a page of second booklet is a Poisson random variable with mean 0.3.
Average error for 7 pages booklet and 5 pages booklet series is:
λ = 0.2×7 + 0.3×5 = 2.9
According to Poisson distribution: 
Where
is average number of events.
The probability of more than 2 typographical errors in the two booklets in total is:

Substitute the respective values in the above formula.



Hence, the required probability is 0.55404.