Select the lines that represent functions

B,D and E are functions.

Step-by-step explanation:

" A function is a process or a relation that associates each element x of a set X, the domain of the function, to a single element y of another set Y (possibly the same set), the codomain of the function "

From the graph we can also check that any line passing through the domain and parallel to co-domain should intersect the graph exactly once.

Clearly from the graph of the functions we could see that:

Graph A:

Has many images corresponding to x= -6.

Hence, A is not a function.

Graph B:

B is a function as corresponding to every point in domain the image is unique. Also by making a line passing through the domain and parallel to the codomain the line intersect the graph exactly at one point.

Graph C:

C is not a function as it has two images for some points.

Graph D:

D is a function as it has unique image corresponding to every x-value.

Graph E:

E is also a function as it has unique image corresponding to every x-value.

, and

for

step-by-step explanation:

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

note the following:

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

$119.20

step-by-step explanation:

$372.50 - 60% off is $149. $149-20% off is $119.20