Practice problem
Find the explicit formula for the geometric sequence. 128,64,32,16,8,4,…128, 64, 32, 16, 8, 4, \dots128,64,32,16,8,4,…
an=(12)na_n =(\frac{1}{2}) ^ nan=(21)n
an=128⋅(12)na_n = 128 \cdot (\frac{1}{2}) ^ nan=128⋅(21)n
an=128⋅(12)(n−1)a_n =128\cdot (\frac{1}{2})(n-1)an=128⋅(21)(n−1)
an=128⋅(12)n−1a_n =128\cdot (\frac{1}{2}) ^{n-1}an=128⋅(21)n−1
Type a concept, like “slope” or “photosynthesis”.
