Question

Which function does NOT represent exponential decay?
y=.4(.5)^x
y=4(.5)^x
y=5(.4)^x
y=5(4)^x

Answer 1

decay is
y=ab^x where 0<b<1

we see the options

0<0.5<1, yep
0<0.5<1, yep
0<0.4<1, yep
0<4<1, nope

aswer is las one

Answer 2

y=5(4)x is correct answer.