Question

Select all the exponential functions that have a percentage rate of change of 19%

A) f(x)=3182(0.9)^2x
B) f(x)=1.74(0.81)^3x
C) f(x)=0.2(0.38)^x/2
D) f(x)= 156(1-0.19)^x

Please Help

Answer 1

B) f(x)=1.74(0.81)^3x

and

D) f(x)=156(1-0.19)^x

Explanation:

The percentage will always be where the b is, or inside the parentheses. You just have to make sure that, when not greater than 1, you must find out WHAT SUBTRACTS FROM 1 TO GET THAT RESULT. So ask yourself, what decimal number subtracts from 1 to get 0.81?

0.81 is the equivalent to (1-0.19) because (1-0.19) = 0.81.

0.19 is 19%, which is what we're looking for!