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:
Answer: Explicit Rule: a_n=30,000 • 2^n-1
Recursive Rule: a_n = 2a_n-1; a_1 = 30,000
Step-by-step explanation: the explicit rule for a geometric sequence is a_n = a_1 • r^n-1 and the recursive rule is a_n= r • a_n -1.
a_1 is the first term of the sequence, which is this case is 30,000. R is the common ration, which is 2 since it doubles each time. Substitute those numbers into the formulas and that’s what you’ll get. Hope this helps. God bless you!!!
Answer: $ 1792
Step-by-step explanation:
Answer:
121.50
Step-by-step explanation:
Let x be the earnings
2x+10 = 253
Subtract 10 from each side
2x+10-10 = 253-10
2x = 243
Divide by 2
2x/2 = 243/2
x = 121.50
Standard deviation = √(n * p * q)
You are given n and p
q = 1 - p
q = 1 -0.2 = 0.8
Standard deviation = √(21 * 0.2 * 0.8)
=√3.36 = 1.83
The answer is A.