What are the explicit equation and domain for a geometric sequence with a first term of 4 and a second term of -12

Explicit formula is:

aₙ = 4(-3)ⁿ⁻¹

The domain of the above formula is:

-∞<n<∞

Step-by-step explanation:

The explicit equation can be found by using the formula

aₙ = a₁ (r)ⁿ⁻¹

Where

a₁ is the first term and

r is the common ratio

We are given a₁ = 4 and a₂ = -12

r = -12/4 = -3

So, explicit formula is:

aₙ = 4(-3)ⁿ⁻¹

The domain of the above formula is:

-∞<n<∞

look at the picture.

y-intercept for the function on a picture is 4 → point (0, 4).

y-intercept for the function

is for x = 0. substitute:

y-intercept is 8 → point (0, 8).