Question #7b5bc

1 Answer
Jan 15, 2018

See explanation.

Explanation:

Given that #D(x)=2x#:

#D(x)# is definitely a function since each input generates exactly one output. So that's true.

#x# is the independent variable since you pick an #x# and it determines #D(x)#.

#D(6)= 2*6=12# so #D(6) ne 3#.

#D(x)# is a direct variation since if we let #D(x)=y# then #y=2x# which is direct variation with constant #k=2#

All of the points in the set #{(5,10), (6,12), (-2,-4)}# definitely fit the rule #y=2x#, so this one is true.