range and domain?

[Lindsie]

which problem is range and which is domain?

1. square root of (x-3) 2. -2-square root of (x+3)

 

[arthur ohlsten]

Only functions have domains and ranges.
You can determine a function by drawing a vertical line, it only crosses the curve once.
A MORE RIGEROUS DEFINITION IS THERE IS ONLY ONE Y VALUE FOR A X VALUE

neither of the expressions y=[x-3]^1/2 or y=[x+3]^1/2 is a function,
They are a relationship

y=[x-3]^1/2 square both sides
y^2=x-3 rewrite
x=y^2+3 a parabola open right vertex at 3,0

the other is also a parabola

Arthur

 

[ElleHCimaras]

Okay, I need some help myself on range and domain. I have to give the range and domain of these equations. I have them graphed out, but I don't understand how to come up with range and domain...

1) y = -4x + 1

2) y = |x - 1|

Thanks...

 

[stapel]

Please post new questions as new threads, not as replies to old threads. Thank you.

Eliz.

P.S. If you have them graphed, then just look on the graphs to find the x-values (the domain) and the y-values (the range).

 

[ElleHCimaras]

Sorry about posting in the wrong thread. The book shows the range and domain in the form of an inequality...which is the part I don't understand how to get. The book doesn't go into great detail on how they came up with the answers.

~Elle