Functions and Relation

True or False: A graph represents a function if and only if each vertical line intersects the graph at most once.

• TRUE

• FALSE

Give a function C that can represent the cost of buying x meals, if one meal costs P40.00.

• C(x)=40

• C=40x

• C(x)=40x

• C(x)=40+x

Determine if the relation is a function

• Not a function, each input has more than one output

• Yes it is a function, because each input has exactly on output

• Not a function, input is equal to output

• Yes it is a function, -1/2 is a fraction of 2

Is this mapping a function or not a function? 

• Function

• Not a Function 

Is the relation a function? Why.

• Yes, because the x-value 11 has two y-values pair with it.

• Yes, because each x-value has only one y-value paired with it.

• No, because the x-value 11 has two y-values pair with it.

• No, because each x-value has only one y-value paired with it.

Is this mapping a function or not a function? 

• Function

• Not a Function 

If f(x)= ax+b, where a and b are integers, f(-1)=-5 and f(3)=3, then a and b are equal to

• a=-3, b=-1

• a=2, b=-3

• a=0, b=2

• a=2, b=3

Which of the following functions from ℤ to ℤ are bijections?

• f(x)=x³

• f(x)=x+2

• f(x)=2x+1

• f(x)=x²+1

For real numbers x and y define xRy if and only if x-y+sqrt root(2) is an irrational number. Then the relation R is

• Reflexive

• Symmetric

• Transitive

• none of the above

Is this a function?

• True

• False