b Consider the base of the function. Is it exponential growth or decay?
A
aB
B
bA
Practice makes perfect
a Let's examine the given equation.
a_n=20( 4/3 )^(n-1)
We can think of this equation as an exponential growth function with a growth factor of 43.
y=20( 4/3 )^(x-1)
Since 43 > 1, the exponential curve is increasing. The ordered pairs satisfying the equation lie on this exponential curve. The equation matches graph B.
b Let's examine the given equation.
a_n=20( 3/4 )^(n-1)
We can think of this equation as an exponential decay function with a decay factor of 34.
y=20( 3/4 )^(x-1)
Since 34 < 1, the exponential curve is decreasing. The ordered pairs satisfying the equation lie on this exponential curve. The equation matches graph A.
