Into Relations and Functions

If f(a)=f(b) implies that a=b then f is

• not one one

• one one

• not onto

• onto

f:R→R given by f(x)=2x is

• only one one

• only onto

• neither one one nor onto

• bijective

13. f: N→N given by f(x)=x^2 is

• one one

• not one one

• onto

• bijective

f:[0,π]→R given by f(x)=sinx is

• one one

• onto

• not one one

• bijective

Does the graph represent a function?

• Yes, because the vertical line test shows there are no repeating input values

• No, because the vertical line test shows there are repeating input values

Does this mapping diagram represent a function?

• No, because there are repeating input values

• Yes, because there are no repeating input values

If f(x) = 2x + 1, what would be your first step to find f(1)?

• Plug a 1 in for all the x's

• Set the function equal to 1

• Only plug a 1 into the left side

• Only plug a 1 into the right side

Is this graph a function and how can you tell?

• Yes its a function cause it doesn't cross itself

• No it's not a function because it goes through the origin

• No it's not a function because the x value 4 has y values of  -2 & 2

• No it's not a function because the y value 4 has x values of  -2 & 2

Is this table a function and how can you tell?

• Yes its a function because there are not variables for missing numbers

• No it's not a function because the y value 4 repeated

• No it isn't a function because the x value 2 is repeated

• No it's not a function because the x value 5 has y values of  10 & 12

For the function {(0,1), (1,-3), (2,-4), (-4,1)}, write the domain and range.

• D: {1, -3, -4,}
  R: {0, 1, 2, -4}

• D:{0, 1, 2, -4}
  R:{1, -3, -4}

• D:{0, 1, 2, 3, 4}
  R:{1, -3, -4}