Answer :
The value of the exponential function, f(x), when x = 18 is 14.44
What is an exponential function?
An exponential function is a function that consists of a constant term that has an index of the argument of the function, or in which the argument of the function is an index of a constant.
The general form of an exponential function is presented as follows;
- f(x) = a·bˣ + k
The value of f(0) is left out in the information, therefore, where k = 0, we get;
f(x) = a·bˣ
From the question, we get;
f(4) = 25, therefore;
f(4) = 25 = a·b⁴
f(11) = 19, therefore;
f(11) = 19 = a·b¹¹
f(4)/f(11) = 25/19 = a·b⁴/(a·b¹¹) = b⁻⁷
b⁷ = 19/25
b¹⁸ = b⁷⁺¹¹ = b⁷ × b¹¹
b¹¹ = 19/a
f(18) = a·b¹⁸ = a × b⁷ × b¹¹ = a × b⁷ × b¹¹ = a × (19/25) × 19/a = 19²/25
f(18) = 19²/25
f(18) = 361/25 = 14,44
Learn more about exponential functions here:
https://brainly.com/question/11534388
#SPJ1
