Question

Write the explicit formula that represents the geometric sequence -2, 8, -32, 128

Answer 1

do you know the explicit formula ingerneral

Answer 2

no I don't

Answer 3

ok so explicit formula for geometric sequence is \[a _{n} = a _{1} \times r ^{n-1}\]

Answer 4

where a1 is first term
and r is common ratio
so what is your first term

Answer 5

-2

Answer 6

do you know what is common ratio

Answer 7

sorry its 4

Answer 8

what is 4???

Answer 9

r is 4

Answer 10

you common ratio should be negative
because first term is negative and second positive
so if you have negative ratio then make sense that 2nd term is positive

Answer 11

ok so r is -4

Answer 12

this right make sense :)