Help with this function problem and i really need answers fast.?

Question

the problem is....

What is the range of the function y= -2x - 4 if the domain is {-1,0,1/2,2}?

its a multiple choice answer so here are the choices

A.{-8,-5.-6,-4}

B.{-8,-5,-4,-2}

C.{-5,-4 1/4,4,-3 1/2 }

D.{0,-2,-6,-6 1/2}

and can you please tell me how you did it too because that would be a big help.

thanks!

Answer 1

Put the x values of the domain into your function:

y = -2(-1) - 4 = -2

y = -2(0) - 4 = -4

y = -2(1/2) - 4 = -5

y = -2(2) - 4 = -8

Put all those values together:

R = {-8. -5. -4. -2}

Therefore, your range is B.

Hope this helps!

Answer 2

You need to plug each of the domain values into the formula one after the other and select the answer which matches the values for "y".

y= -2x - 4

-2(-1)-4=

2-4 =

-2  At this point you know that answers A and C are not correct; but answers B and D are still in the running.

-2(½)-4=

-1-4 =

-5  Answer D does not contain a -5, so the correct answer must be B.

Answer 3

B

Answer 4

B- what you do is you take each number in the domain and plug them in for x. for example..

y=-2(-1) - 4

y= 2 - 4

y= -2

remember.. the range of your function is the y values and the domain of your function is the x values