Question

Find the nth term of the sequence

1,-4,9,-16,...

A) an=32
B) an=-2n
C) an=(-2)^n
D) an=(-1)^n • (n)^2
E) an=n^2

Answer 1

I need help please . I can't match any of the answers

Answer 2

hint : all the numbers are squares except there is a negative sign in front of the even number squares

Answer 3

- so there is an n^2 involved in the nth term

Answer 4

Ok sorry why is there a negative only on the even numbers ,what formula match the sequence

Answer 5

yes - i was thinking that an was = D
but thats not correct

Answer 6

because first term when n = 1
would be (-1)^1 * (1)^2 = -1 * 1 = -1 not 1

Answer 7

None of the options fit the sequence
correct an would be (-1)^(n-1) * (n)^2

here a1 = (-1)^0 * (1)^2 = 1*1 = 1
a2 = (-1)^1 * (2)^2 = -1*4 = -1
a3 = (-1)^2 * (3)^2 = 1 * 9 = 9

Answer 8

I know ,so all of them are wrong ?

Answer 9

yes

Answer 10

could there be a typo somewhere?

Answer 11

D is the closest

Answer 12

D would give a sequence -1,4,-9,16

Answer 13

Oh ok ,thank you

Answer 14

yw