## anonymous one year ago I WILL MEDAL The price of products may increase due to inflation and decrease due to depreciation. Derek is studying the change in the price of two products, A and B, over time. The price f(x), in dollars, of product A after x years is represented by the function below: f(x) = 0.69(1.03)x Part A: Is the price of product A increasing or decreasing and by what percentage per year? Justify your answer. (5 points) Part B: The table below shows the price f(t), in dollars, of product B after t years: t (number of years) 1 2 3 4 f(t) (price in dollars) 10,100 10,201 10,303.01 10,406.04

1. anonymous

Which product recorded a greater percentage change in price over the previous year?

2. anonymous

@IrishBoy123

3. anonymous

@Kainui @ganeshie8

4. anonymous

5. anonymous

6. anonymous

I only need part B and c (help with), because a is: 12500(0.82)=10250, so it is decreasing by 2250, right?

7. anonymous

8. anonymous

please helllppp Wait, I need a too, because i dont know what percent?

9. anonymous

@saseal

10. anonymous

@ali2x2

11. anonymous

what is 0.69(1.03)

12. anonymous

.7107

13. anonymous

what happens if you multiply any number by something smaller than 1?

14. ali2x2

k

15. ali2x2

PART I You know that this function is DECREASING because 0.63, the number inside of the parenthesis, is LESS THAN THE NUMBER 1. I [think I] know the way to determine by what percentage it is decreasing. [I think] My teacher taught me that I have to subtract the number, in this case 0.63, from 1. So, 1 - 0.63 = 0.37. So it is decreasing by 0.37.

16. anonymous

this thing is pretty intuitive

17. ali2x2

|dw:1438873866977:dw|

18. ali2x2

part B

19. ali2x2

im sorta confused sorry ;c ill do a google search

20. ali2x2

lmao or mr.doge here can help?

21. anonymous

sure

22. anonymous

what just happened..

23. anonymous

you got the first part right yet?

24. anonymous

ehhhh I am not sure, as of right now i have that it is decreasing by 37%

25. anonymous

0.69(1.03)=7.107 1-7.107=28.93%

26. anonymous

.69*1.03 is .7107

27. anonymous

you dont really need to care about whats inside or outside, multiplication is commutative

28. anonymous

yea f(x) = 0.69 * 1.03 * x

29. anonymous

you get it yet?

30. anonymous

The x is an exponent, so it is 1.03*.69^x..

31. anonymous

next time put that ^ sign

32. anonymous

lol sorry I didnt pick up that it didnt show till now, sorry.

33. anonymous

the function is actually increasing in that case

34. anonymous

its an exponential curve

35. anonymous

THE VALUE IN THE PARENTHESIS IS MORE THAN ONE. SO YAHHHH ITS INCREASING.

36. anonymous

so confused omfg

37. anonymous

regard the %, try plugging in x=0 and x=1 into the function

38. anonymous

f(x)=.69(1.03)^0 .69*1 .69, or 69%

39. anonymous

f(x)=.69(1.03)^1 .69* 1.03 .7107

40. anonymous

ok now take$f(1)-f(0)$

41. anonymous

.7107-.69

42. anonymous

yes

43. anonymous

.0207

44. anonymous

what % is 0.0207 of 0.69?

45. anonymous

.00014283

46. anonymous

wrong

47. anonymous

I am not sharp. Can you help?

48. anonymous

$\frac{ 0.0207 }{ 0.69 } \times 100$

49. anonymous

3

50. anonymous

3% increase

51. anonymous

part b is easy

52. anonymous

take year 2 - year 1

53. anonymous

okayy. so 101

54. anonymous

now find the percentage like what you just did for the previous part

55. anonymous

101%?

56. anonymous

no 10.1%?

57. anonymous

$\frac{ 10201-10100 }{ 10100 } \times 100$

58. anonymous

1%

59. anonymous

yes

60. anonymous

now the answer for part b is in front of you compare % of product a & b

61. anonymous

okay so product a: 3%, product b=1%?

62. anonymous

yes, and which is greater?

63. anonymous

PRODUCT A?

64. anonymous

yea

65. anonymous

66. anonymous

np

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