Question

Match each exponential function to the description of its percent rate of change. 22% growth 12% decay 2% decay 20% growth 20% decay 22% decay 2% growth 12% growth. f(x) = 44(0.88)^x, f(x) = 124(1.22)^x, f(x) = 22(0.8)^x, f(x) = 42(1.12)^x

Answer 1

The exponential function is defined as y = a(1+r)^x, where "a" represents the original account and "r" the rate of growth or decay.

Then we have the following:

1) 22% grow

y = a( 1 + 22%/100 )^x = a(1.22)^x

So the solution is: 124(1.22)^x

2) 12% decay

y = a( 1 - 12%/100 )^x = a(0.88)^x

So the solution is: y = f(x) = 44(0.88)^x

3) 20% decay

y = a( 1 - 20%/100 )^x = a(0.8)^x

So the solution is: f(x) = 22(0.8)

4) 12% Groth

y = a( 1 + 12%/100 )^x = a(1.12)^x

So the solution is: f(x) = 42(1.12)^x