Given the set of inputs {-4,-1,0,1,4} determine if the following relation is a function. if not explain. 1) 2x+7 ...what am I suppouse to do?

Question

anonymous · Answer

You can plug each of those values into the equation and make sure that no one x value has more than one y-value. The simple answer is that it can't since the function is linear.

zzr0ck3r · Answer

you must show that if x = y then f(x) = f(y) so ...
x = y
2x=2y
2x+7=2y+7
f(x)=f(y)

zzr0ck3r · Answer

and you must show that all of the domain(inputs) map to somewhere . In other words it is ok to plug in all the inputs. And in this case it is.

anonymous · Answer

So is 2x+7 a function or not?

zzr0ck3r · Answer

yes

anonymous · Answer

What about |x|? How will that work with the inputs?

anonymous · Answer

For any conceivable value of x that you put in, do you get out exactly one y?

anonymous · Answer

I guess

anonymous · Answer

Well, can you think of ANY value of x that will give you 2 numbers back? You can also look at it graphically. This is what |x| looks like:
|dw:1343883995672:dw|

anonymous · Answer

When you start seeing this, you're not in function territory:
|dw:1343884027743:dw|