## anonymous one year ago help! graphing piece wise function

1. anonymous

@peachpi

2. anonymous

|dw:1439342436794:dw|

3. anonymous

this is the graph I'm working on

4. anonymous

@Hero @nincompoop @pooja195

5. anonymous

what's the function?

6. anonymous

It doesn't give the whole function to me

7. anonymous

|dw:1439342819554:dw|

8. anonymous

this is what I have, the functions are missing, the graph I drew above is supposed to be interpreted so the function can be filled in

9. anonymous

oh ok. are you sure the bottom one is -3≤x≤3? It looks like it should be 3 ≤ x ≤ maybe 4 or 5

10. anonymous

and is it a curve or a straight line for |dw:1439343210666:dw|

11. anonymous

straight

12. anonymous

yes I'm sure the numbers are correct, The point is just big

13. anonymous

can you take a picture of the problem or give me coordinates for the points? |dw:1439343890005:dw|

14. anonymous

once you have the two end points for the bottom segment, we can write an equation in y = mx + b form, but we need the exact points to get it right

15. anonymous

That's the graph they gave me in the lesson, it's not precise

16. anonymous

the points are -1,1 and 3,5

17. anonymous

-1,1 is a straight line

18. anonymous

3, 5 is a sloped line

19. anonymous

that runs between 3,2 and 5,4

20. anonymous

the equation they give me is |dw:1439344737330:dw|

21. tkhunny

The regions CANNOT overlap if it is the definition of a FUNCTION.

22. Loser66

|dw:1439344850372:dw|

23. anonymous

yes @Loser66

24. Loser66

ok, for the first piece, f(x) = 3 when $$-1\leq x\leq 1$$, got this part? |dw:1439345082272:dw|

25. anonymous

yes

26. Loser66

for the second piece, it is a slant line. Can you find the equation of that line by finding the slope??

27. Loser66

|dw:1439345172848:dw|

28. anonymous

the slope is 1

29. anonymous

or 2/2

30. Loser66

yup, now, pick one point

31. anonymous

1,1

32. Loser66

nope, the point ON the line. (given points)

33. Loser66

|dw:1439345247505:dw|

34. Loser66

which one??

35. Loser66

just pick, either of them.

36. anonymous

0,3

37. Loser66

(0,3) is NOT on the given line.

38. Loser66

YOu have only 2 given points (3,2) and (5,4). Pick one of them. YOu CANNOT pick other point

39. anonymous

3,2

40. Loser66

ok, the line is y = mx +b where m is the slope. And we know that m =1 hence y = x +b -x both sides, what do you get?

41. Loser66

|dw:1439345490498:dw|

42. Loser66

My method is too difficult to understand??

43. tkhunny

Just graph the two pieces as if no restriction existed. Later, go cross out the stuff where the Domain is not specified.

44. Loser66

@tkhunny they didn't give the function. We have to find it. That is the problem $$f(x) =\begin{cases}--------if~~-1\leq x\leq1\\---------if~~~3\leq x\leq 5\end{cases}$$

45. tkhunny

I see. We're given the graph? @Kaelyn78 , you should know the two-point form of a line - or its cleaner variant, the point-slope form. Heard of them?

46. tkhunny

Please stop saying "function" when the Domains overlap.

47. anonymous

I've heard of point slope form

48. tkhunny

Given the two points, calculate the slope. Use one of the points and the slope and fill in the values from the point-slope form. You will be done in no time.

49. Jack1

u say that about calculating 2nd order derivatives of complex equations tho @tkhunny u crazy mathlete u ;)