## shelby1290 one year ago A golf ball is hit and its height is given by the equation h=29.4t - 4.9t^2, where t is the time elapsed, in seconds, and h is the height in metres.

1. shelby1290

a) Write an equation in function notation to represent the height of the ball as a function of time b) State the degree of this function and whether the function is linear or quadratic. c) Use difference tables to confirm your answer in part (b) d) Graph the function where {tER | t > 0} e) At what time(s) is the ball at its greatest height? Express the height of the ball at this time in function notation f) At what time (s) is the ball on the ground? Express the height of the ball att this time in function notation

2. diamondboy

Hi

3. shelby1290

4. shelby1290

@diamondboy ^

5. diamondboy

I think some could be done

6. diamondboy

how far have u gone?

7. diamondboy

Lets start from the very last question (f)

8. diamondboy

What is the height when it touches the ground

9. shelby1290

I haven't started it because i don't understand what to do... Why can't we start from part a) ?

10. shelby1290

And go in order?

11. diamondboy

12. diamondboy

|dw:1442180642592:dw| Do you understand how that happened

13. shelby1290

yes because you put it in function notation

14. diamondboy

yes....so lets go to the next one

15. diamondboy

so it's in the second degree therefore it is what?

16. shelby1290

17. diamondboy

good

18. diamondboy

wat do u think abt question d and f

19. shelby1290

@diamondboy How do you make a graph for {tER | t > 0} in part d?

20. diamondboy

If I could figure out what the tER meant?

21. shelby1290

{TER | T > 0} TER = any real number

22. diamondboy

Ok

23. diamondboy

So thats good that means we would have to pick any real number greater than 0, make a table and graph our data

24. shelby1290

yes

25. shelby1290

|dw:1442183048636:dw|

26. shelby1290

@diamondboy like that? ^

27. diamondboy

yes

28. diamondboy

is that good?

29. shelby1290

|dw:1442183871319:dw|

30. shelby1290

@diamondboy all of the 2nd differences are constant. they add up to -9.8. That makes it quadratic

31. shelby1290

How do i graph it ?

32. diamondboy

You simply|dw:1442184273390:dw|

33. shelby1290

|dw:1442184408996:dw|

34. shelby1290

my line isn't perfect but something like that, right?

35. diamondboy

|dw:1442184387663:dw|

36. diamondboy

something like that but you should have a curve

37. diamondboy

is this a calc 1 class

38. shelby1290

so its at its highest point at 3 seconds or f(3)= 29.4 (3) - 4.9 (3)^2 in function notation ?

39. shelby1290

This is 11th Grade Functions (i'm from Canada)

40. diamondboy

ok

41. diamondboy

hmmm...the reason I asked is I wanted to use the first derivative to find the maximum height

42. shelby1290

and the ball is at the ground at 0 f(0) = 29.4 (0) -4.9(0)^2

43. shelby1290

Oh i don't remember learning about first derivatives

44. diamondboy

but from the graph the highest point is at 3 seconds...and remember u are not using "f" you are using h

45. diamondboy

well yes you could do the last one like that or equate d equation to 0

46. shelby1290

alright so... h(3)= 29.4 (3) - 4.9 (3)^2

47. shelby1290

how do you equate the equation to 0?

48. diamondboy

|dw:1442184935394:dw|

49. diamondboy

you see that?

50. shelby1290

oh okay, you evaluated it....

51. shelby1290

Alright, well thank you so much for helping me!

52. diamondboy

Thank God

53. diamondboy

Moreover you also did a great job

54. shelby1290

thanks

55. diamondboy

Thank God... :)