Question: 2) Draw the graphs of i) $f(x) = |x-2|$ ii) $f(x) = \begin{cases} 1-x, & x < 0 \\ 1, & x = 0 \\ 1+x, & x > 0 \end{cases}$
3) $A = \{-2, -1, 1, 2\}$, $f(x) = \{(x, \frac{1}{x}) : x \in A\}$.
$D_f$, $R_f$ -> ?
1. **Problem Statement:**
We need to draw the graphs of two functions and analyze the domain and range of a discrete function.
2. **Function 1:** $f(x) = |x-2|$
- This is an absolute value function shifted right by 2 units.
- The graph is a V-shape with vertex at $(2,0)$.
3. **Function 2:**
$$f(x) = \begin{cases} 1-x, & x < 0 \\ 1, & x = 0 \\ 1+x, & x > 0 \end{cases}$$
- This is a piecewise linear function with three parts.
- For $x<0$, the graph is a line with slope $-1$ and intercept $1$.
- At $x=0$, the function value is $1$.
- For $x>0$, the graph is a line with slope $1$ and intercept $1$.
4. **Discrete function:**
$$A = \{-2, -1, 1, 2\}$$
$$f(x) = \{(x, \frac{1}{x}) : x \in A\}$$
- Domain $D_f = A = \{-2, -1, 1, 2\}$.
- Range $R_f = \left\{ \frac{1}{-2}, \frac{1}{-1}, \frac{1}{1}, \frac{1}{2} \right\} = \{-\frac{1}{2}, -1, 1, \frac{1}{2}\}$.
5. **Graph shapes and positions:**
- $f(x) = |x-2|$ is a V-shape centered at $x=2$, positioned top-right.
- The piecewise function has three linear branches with a point at $(0,1)$, positioned top-right.
- The discrete function has points at $(-2,-\frac{1}{2}), (-1,-1), (1,1), (2,\frac{1}{2})$, positioned bottom-left.
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### Step-by-step for $f(x) = |x-2|$:
1. The absolute value function is defined as $|u| = \begin{cases} u, & u \geq 0 \\ -u, & u < 0 \end{cases}$.
2. Here, $u = x-2$.
3. So,
$$f(x) = \begin{cases} x-2, & x \geq 2 \\ -(x-2) = 2 - x, & x < 2 \end{cases}$$
4. This forms a V-shape with vertex at $(2,0)$.
### Step-by-step for the piecewise function:
1. For $x<0$, $f(x) = 1 - x$ is a line with slope $-1$ and y-intercept $1$.
2. At $x=0$, $f(0) = 1$.
3. For $x>0$, $f(x) = 1 + x$ is a line with slope $1$ and y-intercept $1$.
4. The graph has a sharp corner at $(0,1)$.
### Step-by-step for discrete function $f(x) = \frac{1}{x}$ on $A$:
1. Domain $D_f = A = \{-2, -1, 1, 2\}$.
2. Calculate range:
- $f(-2) = -\frac{1}{2}$
- $f(-1) = -1$
- $f(1) = 1$
- $f(2) = \frac{1}{2}$
3. Range $R_f = \{-1, -\frac{1}{2}, \frac{1}{2}, 1\}$.
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**Final answers:**
- $D_f = \{-2, -1, 1, 2\}$
- $R_f = \{-1, -\frac{1}{2}, \frac{1}{2}, 1\}$