The value of the function f (x) = 3x² - 25x + 42 at f (-3) is determined as 144. (Option D).
How to calculate the value of f (-3)?
The value of the function at f (-3) is calculated by applying the following formula as shown below.
The given function is as follows;
f (x) = 3x² - 25x + k
The factor of the function = x - 6
The zero of the function becomes;
x - 6 = 0
x = 6
The value of f(6) is calculated as follows;
f(6) = 3(6²) - 25(6) + k
f(6) = - 42 + k
Also f(6) = 0
0 = - 42 + k
k = 42
The value of f (-3) is calculated as follows;
f(-3) = 3(-3)² - 25(-3) + 42
f(-3) = 144