Write an exponential function y = ab^x for a graph that passes through (2, 1) and (3, 8).

Answer 1

Since (2,1) is on the graph, 1 = ab².

Since (3,8) is on the graph, 8 = ab³.

a = 1/b², so 8 = (1/b²)b³ = b

a = 1 / (8)² = 1/64

y = (1/64)(8)^x