Find a formula for the exponential function passing through the points (-2, 2/9) and (1, 6).
let y = a r^x
for (1,6) ----> 6 = a r or a = 6/r
for (-2, 2/9)
2/9 = a r^-2
2/9 = a/r^2
(2/9)r^2 = a
(2/9)r^2 = 6/r
r^3 = 27
r = 3, then a = 2
y = 2(3)^x