Answer:
30 miles²
Step-by-step explanation:
To solve the area of the prism we have to multiply the area of the base * the height of the prism. The base of the prism is a right triangle.
<em>(b*h)÷2 = Area of a triangle</em>
<em />
<em>Base = 4</em>
<em>Height = 3</em>
<em>Now:</em>
<em>(4*3)/2 = 6 miles²</em>
<em />
<em>Now we have to multiply 6 miles² by 5 as our height.</em>
<em />
<em>We get 30 miles² as the volume of the figure.</em>
The estimate between 2 and 9 is 7
I don't know what method is referred to in "section 4.3", but I'll suppose it's reduction of order and use that to find the exact solution. Take

, so that

and we're left with the ODE linear in

:

Now suppose

has a power series expansion



Then the ODE can be written as


![\displaystyle\sum_{n\ge2}\bigg[n(n-1)a_n-(n-1)a_{n-1}\bigg]x^{n-2}=0](https://tex.z-dn.net/?f=%5Cdisplaystyle%5Csum_%7Bn%5Cge2%7D%5Cbigg%5Bn%28n-1%29a_n-%28n-1%29a_%7Bn-1%7D%5Cbigg%5Dx%5E%7Bn-2%7D%3D0)
All the coefficients of the series vanish, and setting

in the power series forms for

and

tell us that

and

, so we get the recurrence

We can solve explicitly for

quite easily:

and so on. Continuing in this way we end up with

so that the solution to the ODE is

We also require the solution to satisfy

, which we can do easily by adding and subtracting a constant as needed:
JG = GK
Angle JGH is a right angle
Angle HGK is a right angle assuming it is drawn like this (sorry i did my best to draw it):
H
l
l
l
l
J--------------l--------------K
G