Answer:
Required series is:

Step-by-step explanation:
Given that
---(1)
We know that:
---(2)
Comparing (1) and (2)
---- (3)
Using power series expansion for 


![=-[c+\sum\limits^{ \infty}_{n=0} (-1)^{n}\frac{x^{2n+1}}{2n+1}]](https://tex.z-dn.net/?f=%3D-%5Bc%2B%5Csum%5Climits%5E%7B%20%5Cinfty%7D_%7Bn%3D0%7D%20%28-1%29%5E%7Bn%7D%5Cfrac%7Bx%5E%7B2n%2B1%7D%7D%7B2n%2B1%7D%5D)


as

Hence,

1. 13*13*13 =2197
2. 2/5*2/5 = 4/25
3. 0.9*0.9 = 0.81
Answer:
1. Her time in minutes is 720/s minutes
2. Given her time to be 20 minutes, her speed is 36 mph
Step-by-step explanation:
Mathematically,
Distance = speed * time
In this question, we want to calculate time;
So time = distance/speed
times = 12 miles/s mph = 12/s hours
Now we want our answer in minutes
Kindly recall that 60 minutes = 1 hour
So 12/s hours will be 12/s * 60 = 720/s minutes
2. Since she drives from home to the office in in 20 minutes, we want to calculate her speed in mph
From the time calculated above i.e 720/s
We can equate 20 = 720/s
20s = 720
s = 720/20
s = 36 mph
Answer is D You'll do the diameter squared then you multiply by π