Question

Help

Answer 1

Select all of the following tables which represent y as a function of x.
x y
0 -2
3 1
6 5
9 8
3 1


x y
0 -5
2 1
6 5
8 9
10 11


x y
-4 -1
2 3
2 4
7 8
13 15


x y
-3 -1
3 1
4 1
8 7
15 13

Answer 2

@jim_thompson5910

Answer 3

last one I promise lol

Answer 4

ok one sec while I read it over

Answer 5

ok not too bad

Answer 6

Rule: a function is basically a rule tying x and y together such that each x input value produces EXACTLY ONE y output value

for example, y = 2x+5 is a function because every/any x you plug in results in exactly one y output

if you had a table where the x's repeat themselves, then you don't have a function because you have multiple outputs for the same input. For example, say we had this table

x y
1 5
2 0
1 -3
4 10

we see that x = 1 maps to both y = 5 and y = -3 at the same time. So we do NOT have a function with this example table

Answer 7

hmmm...... I don't quite understand

Answer 8

sorry im very slow

Answer 9

So the first one is a function because they don't repeat

Answer 10

Imagine I told you that it was 20 degrees Celsius outside. What is that temperature in Fahrenheit?

Answer 11

68

Answer 12

how did you find that value

Answer 13

you used a formula right?

Answer 14

Change 20 degrees Celsius to Fahrenheit: 20*9/5 + 32
20 times 9 is 180.
Then 180 divided by 5 is 36.
Finally, 36 plus 32 is 68 degrees Fahrenheit.

Answer 15

yeah basically you use a formula, this formula actually

F = (9/5)C + 32

the idea is to plug in a value of C and out pops the corresponding value of F. For it to be a function, ONE value of F must come out and not more than one

Answer 16

If you plugged in some temperature, say C = 10, and out popped F = 30 and F = 50 at the same time, you'd be left scratching your head asking yourself "which temperature is the correct one?". So this is why functions have one output per input

Answer 17

yess so I have to figure out what the pattern is in order to know if its a function?

Answer 18

so the shortcut to finding nonfunctions is to look in the x column and look for repeated x values. Then look to the y values to see if they are different. If they are, then we don't have a function

Answer 19

Example