Question

What is the value of t=1 ∑³ (4 x 1/2^t-1)

Answer 1

Answer:

7

Step-by-step explanation:

$\sum\limits_{t=1}^{3}(4\cdot(\frac{1}{2})^{t-1})$

This is the sum of the first three terms of a geometric sequence, where the first term is 4 and the common ratio is ½.

We can use a formula to find the sum, or, since there's only three terms, we can find the value of each term then add up the results.

4 · (½)¹⁻¹ = 4

4 · (½)²⁻¹ = 2

4 · (½)³⁻¹ = 1

4 + 2 + 1 = 7