Question

Given that D(x) = 2x, select all of the following that are true statements.

a- D(x) is a function,
b- xis the dependent variable,
c- D(6) = 3,
d- D(x) is a direct variation,
e- D(x) is a rule for the set of points (5, 10), (6, 12) and (-2, -4).

Answer 1

D(x) is a function ... true or false?

Answer 2

A function is a relation in which each first coordinate in paired with exactly one second coordinate... So false?

Answer 3

for any x you plug in, do you get

a) exactly one output

or

b) more than one outputs

Answer 4

b.

Answer 5

so if you plugged in say x = 9, you would get more than one output?

Answer 6

let's find out

D(x) = 2x

D(9) = 2*9

D(9) = 18

I only see one output, and it's 18

Answer 7

this applies to any x value

plugging in any x value gives you EXACTLY ONE output, so it's a function

Answer 8

So A is one of the answers.

Answer 9

yes

Answer 10

A is true

Answer 11

x is the dependent variable...this is false since x is actually the independent variable

Answer 12

So it cant be B.

Answer 13

correct, how about C? is that true or false?

Answer 14

false?

Answer 15

correct, it's false

Answer 16

how about d?

Answer 17

Direct variation is a function of the form y=kx where k is not zero. So would that be true?

Answer 18

yep, d is true

Answer 19

how about e

Answer 20

i dont know about e.

Answer 21

well if you plug in x = 5, do you get y = 10?