Final answer:
The student's suggested function D(t) = 8400(2)^t + 2 contains a typo and likely should be D(t) = 8400 × 2^t, which is already in the equivalent form of D(t) = ab^t with a = 8400 and b = 2.
Step-by-step explanation:
The student's question about the number of views on a viral video modelled by the function D(t) = 8400(2)^t + 2 requires us to write an equivalent function of the form D(t) = ab^t. In the given function, it seems there is a typo and the plus sign should likely be replaced with multiplication since the form D(t) = ab^t refers to exponential growth without additional terms. Assuming the function should read as D(t) = 8400 × 2^t, it's already in the desired form where a = 8400 and b = 2, so no further transformation is needed. It's important to clarify the function with the student to ensure that typos don't lead to misunderstandings in the mathematical model.