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Practice Quiz: Which Graph Represents a Function?
Sharpen Your Skills: Identify Valid Function Graphs
Study Outcomes
- Analyze graphs using the vertical line test to determine if they represent functions.
- Identify key characteristics that distinguish functions from non-functions.
- Apply reasoning to select the correct graph representing a function.
- Evaluate graphical information to interpret domain and range for given functions.
Function Graph Cheat Sheet
- Vertical Line Test - Think of a vertical line as an x-value spotlight: if it illuminates more than one point on the graph, you lose function status! This quick stunt guarantees each input only leads to one output. Try sketching curves and slicing them up to see who passes the test. Vertical Line Test Guide MathWorld: Vertical Line Test
- Linear Functions - Straight lines are the cool kids of the graph world and always ace the Vertical Line Test - no surprise there! Every x maps to exactly one y, making these functions smooth operators. Spotting them is as easy as checking for constant slope in their equation. Linear Functions Rundown Socratic: Vertical Line Test
- Circles - Circles can be sneaky: a vertical line can slice them at two points, which means they're not functions in the x→y sense. If you draw x²+y²=r², you'll see double y-values for many x's. Remember to watch out for top-and-bottom symmetry! Circles vs. Functions Owlcation: Vertical Line Test Examples
- Parabolas - These U-shaped graphs (like y=x²) always pass the Vertical Line Test since each x shoots to exactly one y. Whether you flip them, shift them, or stretch them, they stay function-friendly. Parabolas rock the single-output rule every time! Parabolas as Functions GeeksforGeeks: Vertical Line Test
- Ellipses & Hyperbolas - Ellipses and hyperbolas can be tricksters: vertical lines often hit them twice, so they're not functions by default. Watch out for both halves of the shape popping up around the axis. You might split them into pieces to make function-friendly sections! Conic Sections Quick Tip Owlcation: Vertical Line Test Examples
- Piecewise Functions - When you glue different rules together by x-intervals, you get piecewise functions. They pass the Vertical Line Test so long as each slice behaves itself with one y per x. Perfect for modeling real-world situations with changing rules! Piecewise Functions Breakdown Owlcation: Vertical Line Test Examples
- Vertical Lines - Ironically, vertical lines like x=3 fail their own test - they hit themselves infinite times! That means they aren't functions of x. Always avoid verticals when defining y as a function of x. About Vertical Lines Socratic: Vertical Line Test
- Horizontal Lines - Horizontal lines (y=5, y=-2, etc.) breeze through the test: each x maps to the same single y. They make for constant functions - super simple and dependable. Spot them by zero slope! Horizontal Lines Explained GeeksforGeeks: Vertical Line Test
- Absolute Value Functions - The classic V-shape of y=|x| always passes the Vertical Line Test. Each x fires off to precisely one y, even if two mirror-image arms appear. Absolute value functions are function-fans for sure! Absolute Value Insights GeeksforGeeks: Vertical Line Test
- Step Functions - Think of a staircase: step functions jump from one y-value to the next without breaking the one-output rule. Each x lands on one flat segment, so they're functions. Great for discrete modeling tasks like rounding or bucket rates! Step Functions Guide Owlcation: Vertical Line Test Examples