Which equations model exponential decay?

Select each correct answer.

y=6(2.1)xy=6(2.1)x

​ y=0.34(0.98)xy=0.34(0.98)x ​

​ y=0.75(1.21)xy=0.75(1.21)x ​

​ ​ y=8(0.28)xy=8(0.28)x ​ ​

Respuesta :

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If it's exponential decay, the number raised to the power will be 0 < x < 1.
The second one and the last one.

Answer:

Option B and D are represents the equation model exponential decay.

Step-by-step explanation:

Exponential decay function is in the form of : [tex]y = ab^x[/tex] where a is the initial value and b≠0,  0<b<1.

Option A:

[tex]y = 6(2.1)^x[/tex]

here a = 6 and b = 2.1 > 1

It is not an exponential decay

Option B

[tex]y = 0.34(0.98)^x[/tex]

here a = 0.34 and b = 0.98<1

Therefore, It is an exponential decay.

Option C:

[tex]y = 0.75(1.21)^x[/tex]

here a = 0.75 and b = 1.21 > 1

It is not an exponential decay

Option D:

[tex]y = 8(0.28)^x[/tex]

here a = 8 and b = 0.28<1

so, it is an exponential decay.