Plz i am confused
15 and or 16

15. It is a function

16. It is a function

Mapping diagram is attached for reference.

Step-by-step explanation:

Mapping diagram is a set of two parallel columns.

The first column includes the 'domain'.

And the second column includes the 'range'.

A relation is a function,

if every domain () has only one range ()

The given coordinates in the set form are in the form ()

15.  We observe that each '' is attached to only one ''

Therefore this relation is a function.

16. We observe that here also each '' is attached to only one ''

Therefore this relation is also a function.

The answer would be (c)

, and

for

step-by-step explanation:

we can analyze the pattern at which the terms increase. let us denote , , , so that we can call

1 the 1st term, 3 the 2nd term, 6 the 3rd term,etc.

note the following:

from the 1st term (1) to the 2nd term (3), we go up by 2,from the 2nd term (3) to the 3rd term (6), we go up by 3from the 3rd term (6) to the 4th term (10), we go up by 4, andfrom the 4th term (10) to the 5th term (15), we go up by 5.

the pattern: to get the next term value, we just add the next term number (e.g. 1st, 2nd, to the previous term value (term values are the given numbers in the question, 1, 3, 6, 10, 15,

from , to get to , we add

from , to get to , we add

etc.

we need to form a recursive formula, a formula that has the next term as a function of the previous term. so a possible recursive formula can be

, and for