Is it a function? Inputs, outputs, domain and range
Grade 8 Math Worksheet - Building Confidence
Circle the best answer, or write your answer on the line.
Read this first
Use the table
input: page output: stickers 4 6 1 3 3 6 2 5 Kira counts the stickers on each page of a sticker book. Page 1 has a shiny dragonfly. Is it a function, and why?
- No: inputs 3 and 4 share the output 6
- Yes: inputs 1, 2, 3 and 4 each have one output
- Yes: no output appears twice, so no count repeats
Luz flies a kite and writes the minute and the meters of string let out. Minute 2 got copied twice by mistake. Is it a function, and why?
- Yes: inputs 2, 4 and 6 each have one output
- Yes: no input appears twice, so no minute repeats
- No: input 2 appears in two rows
On field day, each team plays ball games on one field. Milo draws arrows from team numbers to field numbers. Is it a function, and why?
- Yes: no two arrows land on the same output
- No: inputs 2 and 4 both send an arrow to 8
- Yes: inputs 1, 2, 3 and 4 each send one arrow
Noah weighs boxes for a move. Box 3 got weighed twice on a wobbly scale. The arrows go from box number to pounds. Is it a function, and why?
- No: input 3 sends arrows to 6 and 9
- No: input 1 sends arrows to 4 and 6
- Yes: inputs 1, 3 and 5 each send an arrow
(2, 7), (4, 1), (6, 3), (2, 5). Ren logs (day, laps run) at the track. On day 2 there were two runs, morning and evening. Is it a function, and why?
- No: input 4 has two outputs, 1 and 3
- Yes: inputs 2, 4 and 6 each have an output
- No: input 2 has two outputs, 7 and 5
(1, 3), (2, 5), (3, 5), (5, 8). Tala weighs a puppy each week and writes (week, pounds). In week 3 the puppy chewed a sock, but only the weight counts. Is it a function, and why?
- No: inputs 2 and 3 share the output 5
- Yes: inputs 1, 2, 3 and 5 each have one output
- Yes: no output appears twice, so no weight repeats
Ari checks the snow on the porch and plots (hour, inches). The snow took a break between hours 2 and 4. Is it a function, and why?
- No: the points are not on one straight line
- Yes: inputs 1, 2, 4 and 5 each have one point
- No: (2, 5) and (4, 5) are at the same height
Use the table
input: minute output: birds 3 5 6 2 3 5 8 4 Milo counts birds at a feeder and writes (minute, birds). Minute 3 got copied twice. What is the domain (all the inputs)? List each value once.
(1, 7), (2, 4), (4, 7), (5, 9). Noah plants sunflower seeds and writes (day, seeds sprouted). What is the range (all the outputs)? List each value once.
Pia draws arrows from seed tray number to seeds planted. What is the domain (all the inputs)? List each value once.