High School

Evaluate [tex]f(x)[/tex] when [tex]x=6[/tex].

[tex]
f(x) =
\begin{cases}
3x^2 + 1 & \text{if } -4 < x < 6 \\
6 & \text{if } 6 \leq x < 9
\end{cases}
[/tex]

Options:
A. 109
B. 6
C. 37
D. 9

Answer :

To evaluate the function [tex]\( f(x) \)[/tex] when [tex]\( x = 6 \)[/tex], we need to consider the piecewise definition of the function:

1. If [tex]\(-4 < x < 6\)[/tex], then [tex]\( f(x) = 3x^2 + 1 \)[/tex].
2. If [tex]\( 6 \leq x < 9\)[/tex], then [tex]\( f(x) = 6 \)[/tex].

Since [tex]\( x = 6 \)[/tex] falls in the range [tex]\( 6 \leq x < 9\)[/tex], we use the second piece of the function, which is defined as [tex]\( f(x) = 6 \)[/tex].

Therefore, when [tex]\( x = 6 \)[/tex], the value of the function [tex]\( f(x) \)[/tex] is [tex]\( \boxed{6} \)[/tex].