Is it a function? Inputs, outputs, domain and range
Grade 8 Math Worksheet - Challenge Me
Circle the best answer, or write your answer on the line.
Read this first
Use the table
input: x output: y -2 5 1/2 3 4 -1 -2 5 3 3 6 0 Ren copies a rule table from the board and writes one row twice. Is it a function, and why?
- Yes: inputs -2, 1/2, 3, 4 and 6 each have one output
- No: the outputs do not change by the same amount each time
- No: input -2 appears in two rows
(-7, 3), (2, -4), (5, 3), (2, -4), (-1, 0), (8, 6). Ari collects points from three classmates, and two of them sent the same one. Is it a function, and why?
- No: input 2 appears in two pairs
- No: inputs -7 and 5 share the output 3
- Yes: inputs -7, -1, 2, 5 and 8 each have one output
(3, 1/2), (-2, 4), (3, 2), (6, 4), (0, -3). Bo writes points for a grid design of a kite. Is it a function, and why?
- No: inputs -2 and 6 share the output 4
- Yes: inputs -2, 0, 3 and 6 each have an output
- No: input 3 has two outputs, 1/2 and 2
(4, -2), (-3, 5), (4, -2), (1, 0), (-3, 6). Two inputs repeat in Esme's list of points. One repeat is harmless; one is not. Is it a function, and why?
- No: input 4 appears in two pairs
- No: input -3 has two outputs, 5 and 6
- Yes: inputs -3, 1 and 4 each have an output
Kira plots a zigzag path for a toy car race on a grid. Is it a function, and why?
- Yes: inputs -5, -3, 0, 1, 3 and 5 each have one point
- No: (-3, -1) and (1, -1) are at the same height
- No: the points are not on one straight line
The pond was 14°C at 9 a.m., 19°C at noon and 14°C at 6 p.m. Milo makes temperature the input and time the output. Is it a function, and why?
- No: 14°C goes with two times, 9 a.m. and 6 p.m.
- No: the times are not evenly spaced, so the rule fails
- Yes: every temperature has a time
On a winter day it was -2°C at 6 a.m., 5°C at noon and -2°C at 9 p.m. Noah makes time the input and temperature the output. Is it a function, and why?
- Yes: each time has just one temperature
- No: 6 a.m. and 9 p.m. share -2°C
- No: the temperature goes up, then comes back down
Pia scans library books: barcodes 104 and 117 are two copies of Comet Kids, and 125 is Sea Maps. Input: barcode. Output: title. Is it a function, and why?
- Yes: no title appears twice
- Yes: each barcode has just one title
- No: barcodes 104 and 117 share a title
Ari plots points for a robot's path, and the robot got confused. This graph is not a function. Which input has two different outputs?
Jun's pairs make a function: (1, 4), (3, 6), (5, 4), (6, 9). Which new pair can join and keep it a function?
- (3, 8)
- (5, 1)
- (2, 6)