For the expoential function y= ab^x, which of the following value(s) would produce an expoential decay function?

a. 0< b< 1
b. a< 0
c. b> 1
d. b< 0

Hello.

A decay function has a distinctive comportment: 

"If a < b, therefore f(a) > f(b)"

So, the function must assume smaller values as x grows.

This is accomplished when 0 < b < 1

Im pretty sure it would be 6 purple rectangles.