Answer:
Tn = -n^2 - n + 21 is the formula for the nth term.
Step-by-step explanation:
The second differences are all equal in this quadratic sequence.
Now, the quadratic sequence has a formula of Tn = an^2 + bn + c
Find the value of a in an^2 by dividing the difference by 2:
-2/2 = -1
a = -1
Since T1 is 19 and T2 is 15 we can put that into the equation and simplify:
b + c = 20
2b + c = 19
Thus, b = -1 , c = 19 and the general formula for the nth term is Tn = -n^2 - n + 21
M is the slope so the slope is 1
I would 100 because the more the trials means the more the results which means you get more of an accurate experiment then if you only did 10. Because since you have so many answers from all of the experiments you can conclude the correct answer from all of the experiments. I hope you get what I’m trying to say
Answer:
the answer is 259.9 because the result is 259.8834