Question

Which equations model exponential decay?

Answer 1

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

Answer 2

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.