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10 votes
10 votes
Which rules define the function graphed below? (15 points cuz I'm stumped)

y=2x+3; y=-1/3x+3
y=2x; y=-1/3x
y=3x+2; y=3x-1
y=-3x+3; y=x+3

Which rules define the function graphed below? (15 points cuz I'm stumped) y=2x+3; y-example-1
User Oliver Sosa
by
2.6k points

1 Answer

23 votes
23 votes

Answer: Choice A

y=2x+3; y=-1/3x+3

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Step-by-step explanation:

The left portion of the blue curve is y = 2x+3 but it is only graphed when x < 0 (we could argue that
x \le 0 but I'll set that aside for the other portion).

The right portion is the line y = -1/3x + 3 and it's only graphed when
x \ge 0

So we could have this piecewise function


f(x) = \begin{cases}2x+3 \ \text{ if } x < 0\\-(1)/(3)x+3 \ \text{ if } x \ge 0\\\end{cases}

Or we could easily swap the "or equal to" portion to move to the first part instead like this


f(x) = \begin{cases}2x+3 \ \text{ if } x \le 0\\-(1)/(3)x+3 \ \text{ if } x > 0\\\end{cases}

Either way, we're involving the equations mentioned in choice A

User Andreas Hagen
by
2.6k points
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