nic0olemelinels
Answered

  1. Which best describes the relationship between the successive terms in the sequence shown?

9, –1, –11, –21, …


a)The common difference is –10.

b)The common difference is 10.

c)The common ratio is –9.

d)The common ratio is 9.

  1. A sequence is defined recursively using the formula f(n + 1) = f(n) – 5 . Which sequence could be generated using this formula?

a)1, –5, 25, –125, ...

b)2, 10, 50, 250, ...

c)3, –2, –7, –12, ...

d)4, 9, 14, 19, ...

Verified Answer :

bobo615

The answer is A.) The common difference is -10

JcAlmighty

Q1. The answer is a)The common difference is –10. 

Let's calculate the common difference (c):
c = f(n + 1) - f(n)

9, –1, –11, –21, …
-1 - 9 = -10
-11 - (-1) = -11 + 1 = -10
-21 - (-11) = -21 + 11 = -10


Q2. The answer is c)3, –2, –7, –12, ...

f(n + 1) = f(n) – 5
f(n + 1) - f(n) = -5

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

So, the common difference is: c = -5

Let's check all choices:
a) c = -5 - (-1) = -5 + 1 = -4         INCORRECT
b) c = 10 - 2 = 8                        INCORRECT
c) c = -2 - (-3) = -5
    c = -7 - (-2) = -5
    c = -12 - (-7) = -5                    CORRECT
d) c = 9 - 4 = 5                          INCORRECT

Related Questions