Question

Which equation below will produce a decay curve

y=2(4)^x
y=3^x-4
y=6(1/3)^x
y=1/2(3)^x

Answer 1

answer : y=6(1/3)^x, option C

Decay curve means when x value increases the y value will decrease.

We plug in 3 values for x and check the y value

Lets start with first option

`y=2(4)^x`

x=0 , y= 2

x=1, y= 8

x=2, y=32

when x value increases the y value also increases. so option A is not a decay curve

`y=3^x -4`

x=0 , y= -4

x=1 , y= -1

x=2 , y = 5

when x value increases the y value also increases. so option B is not a decay curve.

`y= 6((1)/(3))^x`

x=0, y = 6

x=1, y = 2

x=2 , y= 0.67

when x value increases the y value decreases. so option C is a decay curve