Question

Whicg is an exponential decay function? thx

Answer 1

The second one is a decay function because the value in parentheses is less than one. 

Answer 2

Hello,

a^x is an exponentiel decay function if 0<a<1

7/4>1
(4/5)^-1 >1
(8/7)^-1 =7/8 <1 ******
9/2 >1

Answer C