SOLUTION: Which function describes exponential decay? a) f(x)=6(1.01)^x b) f(x)=3.4(40)^2x c) f(x)=25(0.8)^x d) f(x)=8(17)^x/4

Algebra ->  Rational-functions -> SOLUTION: Which function describes exponential decay? a) f(x)=6(1.01)^x b) f(x)=3.4(40)^2x c) f(x)=25(0.8)^x d) f(x)=8(17)^x/4      Log On


   

Question 1090743: Which function describes exponential decay?
a) f(x)=6(1.01)^x
b) f(x)=3.4(40)^2x
c) f(x)=25(0.8)^x
d) f(x)=8(17)^x/4
Answer by MathLover1(20850) About Me  (Show Source):
You can put this solution on YOUR website!
In the exponential function f%28x%29=a%5Ex, if a%3C1, the output gets smaller as x gets larger. In this case, f%28x%29 is called an exponential decay function.
let see what is a in your case:
a) f%28x%29=6%281.01%29%5Ex->a=1.01 and a%3E1; unction is an exponential growth
b) f%28x%29=3.4%2840%29%5E2x->a=40 and a%3E1; unction is an exponential growth
c) f%28x%29=25%280.8%29%5Ex->a=0.8 and highlight%28a%3C1%29; unction is an exponential highlight%28decay%29
d)+f%28x%29=8%2817%29%5Ex%2F4->a=17 and a%3E1; unction is an exponential growth

so, your answer is:
c) f%28x%29=25%280.8%29%5Ex->a=0.8 and highlight%28a%3C1%29; unction is an exponential highlight%28decay%29

see its graph:
+graph%28+600%2C+600%2C+-10%2C+20%2C+-10%2C+20%2C+25%280.8%29%5Ex%29+