Shido88 Group Title Determine the value of f(-6), f(3/2), f(2c) and f(c+1), then simplify as much as possible Question : f(x) = 3x^2 - 4x one year ago one year ago

1. Shido88 Group Title

2. Aylin Group Title

Well, in the first two, just take the appropriate number and plug it in where x is. Then simplify it down. For the third one (2c) replace x with 2c, then see what you get. Same for the fourth one. The first two are plug'n'chug, but if you need help with the second two I'll stick around.

3. Shido88 Group Title

the second two, just plug it in to every x in the problem ?

4. Aylin Group Title

Mhm. So f(2c) would like$f(2c)=3 \times (2c)^{2}-4 \times (2c)$

5. Shido88 Group Title

Ok let me try thanks!

6. Shido88 Group Title

ummm question

7. Aylin Group Title

Yes?

8. Shido88 Group Title

kinda dumb question but for the first one f(-6) i did -6=3(-6)^2-4(-6) -6=108+24 -6=132 then at this step do you add the 6 over or minus the 132 over ?? lol

9. Shido88 Group Title

it usually easier if one size has a (x)

10. Aylin Group Title

Well, the left side is f(-6) not -6. So when you get to f(-6)=132, you are finished with that part.

11. Aylin Group Title

Since you've found the value in the range (132) that corresponds to the value of -6 in the domain.

12. Shido88 Group Title

i see

13. Shido88 Group Title

the second one i found is 3/4 hope its right

14. Shido88 Group Title

the third one i got: f(2c) = 4c

15. Shido88 Group Title

and do you divide the 2c over ?

16. Aylin Group Title

I also got 3/4

17. Shido88 Group Title

cool :D

18. Aylin Group Title

Well, with these problems you only need to simplify the right side, don't worry about the left side at all. In the third and fourth ones your answer will be in terms of c though.

19. Shido88 Group Title

so is my answer for the third one okay ?

20. Aylin Group Title

Well, no.$(2c)^{2}=4c^{2}$and there is nothing in there to cancel it, so you should have a c^2 term.

21. Shido88 Group Title

how did you get 2c^2 on the left side ?

22. Shido88 Group Title

isn't it 2c ?

23. Aylin Group Title

$f(2c)=3(2c)^{2}-4(2c)$and$(2c)^{2}=4c^{2}$so$f(2c)=3 \times 4c^{2}-4(2c)$

24. Shido88 Group Title

oh so you can't multiply the term -4 with 2c ?

25. Aylin Group Title

You can, but I was leaving it for you to do. :P

26. Shido88 Group Title

ohhhh lol

27. Shido88 Group Title

at first i thought u can make (2c)^2 = 4c and just X 3 = 12c

28. Shido88 Group Title

i was wrong :|

29. Aylin Group Title

Pretty close, just forgot the ^2 part of it. :P

30. Shido88 Group Title

u mean 12c^2 ?

31. Aylin Group Title

Yep

32. Shido88 Group Title

but why ? :O isn't it already been done on the 2c^2 ?why ^2 another

33. Shido88 Group Title

@___@

34. Aylin Group Title

Well$(2c)^{2}$is the same thing as$2c \times 2c$Does that make it more clear?

35. Shido88 Group Title

does that make 4c ?

36. Shido88 Group Title

and 4c x 3 = 12c lol ?

37. Aylin Group Title

$2c \times 2c = 4c^{2}$

38. Shido88 Group Title

ohhh lol =___=

39. Shido88 Group Title

omg...my mind is somewhere else today....sorry

40. Aylin Group Title

Mine is too, don't worry.

41. Shido88 Group Title

42. Shido88 Group Title

so once i got f(2c) = 12c^2 - 8c then what can i do next?

43. Aylin Group Title

Well, at this point all of the same powers of c are together, so you're done.

44. Shido88 Group Title

what do you mean by "same powers of c are together" ? :d

45. Aylin Group Title

Well, there's only one c^2 term and only one c term. You can't combine the c^2 and the c terms, so there is nothing left to do.

46. Shido88 Group Title

i see

47. Shido88 Group Title

the fourth one im stuck completely :D

48. Aylin Group Title

Well, what is$(c+1)^{2}$?

49. Shido88 Group Title

(c+1)(c+1)

50. Aylin Group Title

So FOIL it out! :P

51. Shido88 Group Title

ohh let see

52. Shido88 Group Title

c^2+2c+1 and i think u can factor it more right ?

53. Aylin Group Title

Well, we don't want to factor it right now. So now$f(c+1)=3 \times (c^{2}+2c+1)-4 \times (c+1)$Can you finish it from there?

54. Shido88 Group Title

kk hold on

55. Shido88 Group Title

i think it is : f(c+1)=3c^2 + 2c -1

56. Aylin Group Title

Yep!

57. Shido88 Group Title

awesome! lol

58. Shido88 Group Title

so is that it ? o_0

59. Aylin Group Title

Yep

60. Shido88 Group Title

cool! thanks Aylin

61. Aylin Group Title

You're welcome.

62. Shido88 Group Title

your really good in math :D genius maybe?

63. Aylin Group Title

Not really, I just want to teach math.

64. Shido88 Group Title

btw are you in college?

65. Shido88 Group Title

oh ! so your a teacher :D

66. Shido88 Group Title

wow! how lucky i am :D

67. Aylin Group Title

Not yet. I'm a senior at RPI.

68. Aylin Group Title

But next year I hope to be a teacher.

69. Shido88 Group Title

70. Aylin Group Title

In May

71. Shido88 Group Title

oh wow, almost there!

72. Shido88 Group Title

how many years did you spend in RPI ?

73. Aylin Group Title

The end of this year will make three years.

74. Shido88 Group Title

that's really quick wow

75. Shido88 Group Title

is this it ? "Rensselaer Polytechnic Institute" ?

76. Aylin Group Title

Yeah. Not really very fast though; I spent two years at another school first.

77. Shido88 Group Title

I see, still not bad. I had a friend who spends 3 years at community college and transfer

78. Shido88 Group Title

what's the GPA for acceptance in RPI?

79. Aylin Group Title

It was a community college that I came from, actually. From another college or from high school?

80. Shido88 Group Title

another college

81. Shido88 Group Title

yeah, everybody is doing community college first now aday, cuz it's so much cheaper :D

82. Aylin Group Title

Minimum is 3.0 Higher is better of course, but they also like it if you've been taking mostly science and math courses (or engineering if that's your major choice) if possible.

83. Shido88 Group Title

make sense.

84. Shido88 Group Title

well thanks so much for talking with me Aylin. I gotta get to dinner now :D

85. Aylin Group Title

Like if you took a lot of math/science courses and made mostly Bs, it would look better than if you had made As taking mostly things like Art or Chorus or History

86. Aylin Group Title

Bye

87. Shido88 Group Title

anything with science and math is better...and it's the subjects that im most terrible at. WOW..

88. Shido88 Group Title

well bye for now :d

89. Aylin Group Title

Well, the other thing is that RPI is about $60000 a year right now, so... 90. Shido88 Group Title your kidding me? no way 91. Aylin Group Title 92. Shido88 Group Title so how much for 1 semester of full time? 93. Shido88 Group Title omg wow... 94. Aylin Group Title About half, but it depends on what your dining plan is, where you live, ect. 95. Shido88 Group Title omg so much debts...well but it's COLLEGE that we're talking about here so no suprise.. :| 96. Shido88 Group Title one time I read that article about this college couples graduated with over 200k debts scared the hell out of me :| 97. Aylin Group Title I'm gonna have about$45K.

98. Shido88 Group Title

did they tell you about the rate? or how much you have to pay back once your graduated ? I mean monthly?

99. Aylin Group Title

At some point probably. I don't remember what it is right now.

100. Shido88 Group Title

oh i see, well i hope you can pay back all the debts without too much trouble :|

101. Aylin Group Title

I should be able to.

102. Aylin Group Title

Which year are you in?