Which relation represents a function?

The relation which represents a function is:

           { (-2,2) , (0,2) , (7,2) , (11,2) }

Function--

A function is a relation such that each element of first set is mapped to a unique element of the other set.

i.e. no element has two images.

i.e. it is  a ordered pair of the type: (x,y)

such that no x is mapped to more than one y.

A)

{ (0,0) , (2,3) , (2,5) , (6,6) }

It is not a function.

since 2 is mapped to 3 i.e. the ordered pair (2,3)

and 2 is mapped to 5 as well i.e. the ordered pair (2,5) .

B)

{ (3,5) , (8,4) , (10,11) , (10,6) }

It is not a function.

since 10 is mapped to 11 in the ordered pair (10,11).

and 10 is mapped to 6 in the ordered pair (10,6) .

C)

{ (-2,2) , (0,2) , (7,2) , (11,2) }

It is a function.

since no element of the  first set is mapped to more than one element of the other set.

D)

{ (13,2) , (13,3) , (13,4) , (13,5) }

It is not a function.

since 13 is mapped to more than one element of the other set.

a box 3 3/4 feet long or 4+ feet.

step-by-step explanation:

answer:  

step-by-step explanation:

here x represents the height of the pole,

and, the height of the shadow of the pole is 12 feet.

also, the angle of elevation from the top of the pole is 40°,

therefore,

by the low of sine,

which is the required equation for finding the value of x,