Question

7. Are the ordered pairs below an arithmetic sequence or geometric

Answer 1

Answer:

8. Arithmetic Progression

9. $f(9) = 300$

Step-by-step explanation:

Given

$\{(1,55)\ (2, 45)\ (3, 35)\ (4, 25)\}$

Solving (8): Arithmetic or Geometric

We start by checking if it is arithmetic by checking for common difference (d).

$d = y_2 - y_1 = y_3 - y_2 = y_4 - y_3$

This gives:

$d = 45 - 55 = 35 - 45 = 25 - 35$

$d = -10 = -10 = -10$

$d=-10$

Because the common difference is equal, then it is an arithmetic progression

Solving (8):

$f(n) = f(1) + f(n-1)$

To find f(9), we substitute 9 for n

$f(9) = f(1) + f(9-1)$

$f(9) = f(1) + f(8)$

We need to solve for f(8); substitute 8 for n

$f(8) = f(1) + f(8 - 1)$

$f(8) = f(1) + f(7)$

We need to solve for f(7); substitute 7 for n

$f(7) = f(1) + f(7 - 1)$

$f(7) = f(1) + f(6)$

We need to solve for f(6); substitute 6 for n

$f(6) = f(1) + f(6 - 1)$

$f(6) = f(1) + f(5)$

We need to solve for f(5); substitute 6 for n

$f(5) = f(1) + f(5 - 1)$

$f(5) = f(1) + f(4)$

From the function, f(4) = 25 and f(1) = 55.

So:

$f(5)=55 + 25$

$f(5)=80$

$f(6) = f(1) + f(5)$

$f(6) = 55 + 80$

$f(6) = 135$

$f(7) = f(1) + f(6)$

$f(7) = 55 + 135$

$f(7) = 190$

$f(8) = f(1) + f(7)$

$f(8) = 55 + 190$

$f(8) = 245$

$f(9) = f(1) + f(8)$

$f(9) = 55 + 245$

$f(9) = 300$