Grade 8 functions quiz: Evaluating from tables and graphs

📚 Quick Study Guide

• 🔢 Function: A relation where each input has only one output.
• 📈 Table: Shows input-output pairs. Check that each input ($x$) has only one output ($y$).
• 📊 Graph: Represents the function visually. Use the vertical line test to check if it's a function.
• 📍 Evaluating from Tables: Find the input ($x$) in the table and read the corresponding output ($y$). That's your answer!
• 🧭 Evaluating from Graphs: Find the input ($x$) on the x-axis, go up (or down) to the graph, and then read the corresponding output ($y$) on the y-axis.
• ➕ Linear Functions: Functions that form a straight line on a graph. Represented as $y = mx + b$.
• ➗ Non-linear Functions: Functions that do not form a straight line. Examples include quadratic ($y = ax^2 + bx + c$) and exponential functions ($y = ab^x$).

Practice Quiz

1. What is $f(2)$ based on the following table?

   x	y = f(x)
   0	1
   1	3
   2	5
   3	7

   1. 1
   2. 3
   3. 5
   4. 7
2. Given the function $f(x)$ represented by the graph (imagine a straight line passing through (0,1) and (1,3)), what is $f(0)$?
   1. 0
   2. 1
   3. 2
   4. 3
3. Using the table below, find the value of $f(4)$.

   x	y = f(x)
   1	2
   2	4
   3	6
   4	8

   1. 2
   2. 4
   3. 6
   4. 8
4. If the graph of $f(x)$ is a horizontal line at $y = 5$, what is $f(2)$?
   1. 0
   2. 2
   3. 5
   4. Undefined
5. Based on the graph (imagine a curve passing through (1,1) and (2,4)), what is the approximate value of $f(1.5)$?
   1. 1.5
   2. 2.0
   3. 2.25
   4. 3.0
6. Given the following table, determine $f(3)$.

   x	y = f(x)
   -1	1
   0	0
   1	1
   2	4
   3	9

   1. 3
   2. 6
   3. 9
   4. 12
7. The graph of a function $f(x)$ passes through the point (3, 7). What is the value of $f(3)$?
   1. 3
   2. 4
   3. 7
   4. 10