# What did I do wrong?

1. Sep 29, 2004

### UrbanXrisis

Why did I get this Math Question Wrong?

Last edited by a moderator: May 1, 2017
2. Sep 30, 2004

### matt grime

Is it supposed to be [0.5x], meaning ceiling? It's hard to make out on my screen

3. Sep 30, 2004

### Leong

i get the same graph as you did. maybe you should ask the fella who marked you question.

4. Sep 30, 2004

### SGT

I think the required answer is a straight line segment from the point (-1,-2) to the point (1,2)

5. Sep 30, 2004

### matt grime

if you look at the scanned image, SGT, the format implies that it ought to be ceiling(0.5x) that is plotted, not 0.5x, i think, though it is a little vague,

6. Sep 30, 2004

### UrbanXrisis

that symbol is the greatest integer function.

7. Sep 30, 2004

### SGT

OK, I had not understood the meaning of the brackets. I think the solution is in the attached picture.

8. Sep 30, 2004

### matt grime

That is also not correct since 0.5*2=1, and ceiling(1) is 1, not two as your diagram shows.

9. Sep 30, 2004

### SGT

My mistake. I was plotting y =[x], instead of y = [0.5x]. If the brackets really mean ceiling, your solution seems correct.

10. Sep 30, 2004

### HallsofIvy

I notice you have "open circles" at the left endpoint of each interval. Did you mean by that (or did whoever marked you wrong interpret that as) that point was not included in the interval? Since "ceiling" of x is the smallest integer greater than or equal to x, the left endpoint of each interval is included in the interval, but the right endpoint is not.

Last edited by a moderator: May 1, 2017