Question

find the domain of the function.
f(x) = -2x

Answer 1

All real numbers.

Answer 2

how do you write that.... bracket-2,infinity parentheses?

Answer 3

It would be (-infinity,infinity)

Answer 4

The domain is the input of the function. You can put anything in for x in this case.

Answer 5

Contrast this with 1/x. That would be all real numbers other than zero since you can't divide by zero.

Answer 6

can you help me with one more hard one

Answer 7

find f(-5)=
f(0)=
f(0.5=
f(1)=
f(4)=

Answer 8

You need to figure out which part of the function to use.

f(-5) means x = -5, -5 < 0 so we use -2x; -2(-5) = 10
f(0) means x = 0, x =0 so we use x - 4, 0 - 4 = -4

The same reasoning applies to the next three.