Answer:
Option B and D are represents the equation model exponential decay.
Step-by-step explanation:
Exponential decay function is in the form of : \(y = ab^x\) where a is the initial value and b≠0, 0<b<1.
Option A:
\(y = 6(2.1)^x\)
here a = 6 and b = 2.1 > 1
It is not an exponential decay
Option B
\(y = 0.34(0.98)^x\)
here a = 0.34 and b = 0.98<1
Therefore, It is an exponential decay.
Option C:
\(y = 0.75(1.21)^x\)
here a = 0.75 and b = 1.21 > 1
It is not an exponential decay
Option D:
\(y = 8(0.28)^x\)
here a = 8 and b = 0.28<1
so, it is an exponential decay.
