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

A

E

D

Explanation:

Answer 2

For D (x) = 2 x:
- x is the independent variable,
- D ( 6 ) = 2 · 6 = 12.
10 = 2 · 5, 12 = 2 · 9, - 4 = 2 · ( - 2 ).
True statements are:
A ) D ( x ) is a function.
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 ).