SOLUTION: Sorry for asking so many questions, but I really need to kow this one: how do I know wheter a relation is a function or not? and how am I supposed to graph this type of equation?

Algebra ->  Functions -> SOLUTION: Sorry for asking so many questions, but I really need to kow this one: how do I know wheter a relation is a function or not? and how am I supposed to graph this type of equation?      Log On


   

Question 82200: Sorry for asking so many questions, but I really need to kow this one: how do I know wheter a relation is a function or not?
and how am I supposed to graph this type of equation? my work sheet says to "graph each equation by plotting ordered pairs" and then it gives me several equations such as this one:
y = 2x - 1

Answer by stanbon(75887) About Me  (Show Source):
You can put this solution on YOUR website!
how do I know whether a relation is a function or not?
A relation is a function if for each value x takes there is only one y value.
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and how am I supposed to graph this type of equation? my work sheet says to "graph each equation by plotting ordered pairs" and then it gives me several equations such as this one:
y = 2x - 1
To graph it you need two points:
If x=0, y=2*0-1 = -1 giving you point (0,-1)
If x=1, y=2*1-1 = 1 giving you point (1,1)
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Plot these two points; draw a line thru them; that is your graph.
graph%28400%2C300%2C-10%2C10%2C-10%2C10%2C2x-1%29
Cheers,
Stan H.