Find [tex]\( f(3) \)[/tex] for the piecewise function.

[tex]\[
f(x)=\left\{
\begin{array}{ll}
x-2 & \text{if } x \ \textless \ 3 \\
x-1 & \text{if } x \geq 3
\end{array}
\right.
\][/tex]

[tex]\( f(3) = ? \)[/tex]



Answer :

To find [tex]\( f(3) \)[/tex] for the given piece-wise function, let's follow these steps in detail:

The piece-wise function [tex]\( f(x) \)[/tex] is defined as follows:
[tex]\[ f(x) = \begin{cases} x - 2 & \text{if } x < 3 \\ x - 1 & \text{if } x \geq 3 \end{cases} \][/tex]

We need to evaluate this function at [tex]\( x = 3 \)[/tex].

1. Identify which part of the piece-wise function to use:
- The function [tex]\( f(x) = x - 2 \)[/tex] is applicable when [tex]\( x < 3 \)[/tex].
Since [tex]\( x = 3 \)[/tex] is not less than 3, this part does not apply.
- The function [tex]\( f(x) = x - 1 \)[/tex] is applicable when [tex]\( x \geq 3 \)[/tex].
Since [tex]\( x = 3 \)[/tex] is equal to 3, this part does apply.

2. Use the correct part of the function to calculate [tex]\( f(3) \)[/tex]:
- Since [tex]\( x = 3 \)[/tex] falls under the condition [tex]\( x \geq 3 \)[/tex], we use [tex]\( f(x) = x - 1 \)[/tex].

3. Substitute [tex]\( x = 3 \)[/tex] in the appropriate part of the function:
[tex]\[ f(3) = 3 - 1 \][/tex]

4. Perform the calculation:
[tex]\[ f(3) = 2 \][/tex]

Therefore, the value of [tex]\( f(3) \)[/tex] is:
[tex]\[ f(3) = 2 \][/tex]