Piecewise Function: Find Expression for Graph | Homework Help

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Homework Help Overview

The discussion revolves around finding an expression for a piecewise function based on a provided graph. Participants are exploring the definitions and intervals associated with the piecewise function, particularly focusing on the endpoints and the continuity at those points.

Discussion Character

  • Conceptual clarification, Assumption checking

Approaches and Questions Raised

  • Participants discuss the intervals for the piecewise function, questioning why certain endpoints are chosen as open or closed. There is an exploration of the implications of these choices on the function's definition.

Discussion Status

The conversation is ongoing, with participants examining different interpretations of the interval notation and its impact on the piecewise function. Some guidance has been offered regarding the validity of different interval choices, particularly at the point where the two functions meet.

Contextual Notes

There is a focus on the definitions of closed and open intervals and how they relate to the continuity of the piecewise function at the transition point of x=3. Participants are considering the implications of their choices within the constraints of the problem.

Rijad Hadzic
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Homework Statement


Hello I uploaded a picture of the image.

Find an expression for a function who's graph is the given curve.

Homework Equations

The Attempt at a Solution


The first function [0,3] y= -x+3 and the second one is y=2x-6 from 3 to 5

what I don't get, is why isn't the second one [3,5], instead the answer is (3,5)..

The way I see it at that point, x=3, it can be anyone of those equations...
 

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My thinking is because the function goes from right to left it would make sense that the first function is less than or equal to 3 but I'm not sure if that's right..
 
Rijad Hadzic said:

Homework Statement


Hello I uploaded a picture of the image.

Find an expression for a function who's graph is the given curve.

Homework Equations

The Attempt at a Solution


The first function [0,3] y= -x+3 and the second one is y=2x-6 from 3 to 5

what I don't get, is why isn't the second one [3,5], instead the answer is (3,5)..

The way I see it at that point, x=3, it can be anyone of those equations...
And that's why you should choose which function goes with which interval. If ##x \in [0. 3]## you use the formula y = -x + 3. If ##x \in (3, 5)##, you use the formula y = 2x - 6.
 
Mark44 said:
And that's why you should choose which function goes with which interval. If ##x \in [0. 3]## you use the formula y = -x + 3. If ##x \in (3, 5)##, you use the formula y = 2x - 6.

So the reason my books answer was [0,3] for y=-x + 3 was because they chose it to be that.

But if I wanted to I could choose [0,3) for y=-x+3 and [3,5] for 2x - 6 and my answer would still be valid because that's what I decided to choose?
 
Rijad Hadzic said:
So the reason my books answer was [0,3] for y=-x + 3 was because they chose it to be that.

But if I wanted to I could choose [0,3) for y=-x+3 and [3,5] for 2x - 6 and my answer would still be valid because that's what I decided to choose?
Yes. At x = 3, both functions have y-values of 0, so it doesn't matter how you define the endpoints of the two intervals.
 

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