Final answer:
The recursive definition for the sequence aₙ=7ⁿ is aₙ+₁ = 7aₙ, with an initial value of 7 for a₁.
Step-by-step explanation:
To give a recursive definition of the sequence aₙ=7ⁿ, we can express the next term aₙ+₁ in terms of the current term aₙ. In this case, aₙ+₁ can be calculated by multiplying aₙ by 7. So the recursive definition is: aₙ+₁ = 7aₙ. The initial value a₁ is 7, since a₁ is the first term of the sequence.