Results 1 to 10 of 10

Thread: +1 rep point for every problem answered (5+ questions) pre-calc help

  1. #1

    Join Date
    Dec 2011
    Gender
    Location
    United States
    Posts
    5,856
    Thanks
    1,493
    Thanked 2,146 Times in 1,216 Posts


    Downloads
    6
    Uploads
    0
    Mentioned
    1092 Post(s)
    Time Online
    42 d 18 h 30 m
    Avg. Time Online
    32 m
    Rep Power
    15

    +1 rep point for every problem answered (5+ questions) pre-calc help

    1. find a formula for f^-1(x) given f(x)=ln(2x-5)

    2.given f(x)=x^3-4x^2-11x+30 (a)find the zeros and (b) write a linear factorization of the function.

    3.You are planning to make an open rectangular box from a 20 by 25in piece of cardboard by cutting congruent squares of side x from the corners and folding up the sides.

    (a) write a funtion V(x)for the volume of the box
    (b)what is the domain of V?
    (c) Graph the function on your calculator and find the maximum volume
    (d) what are the dimmensions of the box yielding the maximum volume?

    4. Solve algebraically. what is the significance of the solution in terms of the graph of the two equations?
    3x-5y=12
    6x-10y=14


    i will +rep a minimum of one point per answered correct question. different parts (a, b, c, ect all count as there own question.)

    also if you answer them all, i will +10 rep you as soon as i can!
    Last edited by John; 04-24-2012 at 10:41 AM.

  2. #2
    Ana's Avatar
    Join Date
    Mar 2012
    Gender
    Location
    No where :P
    Posts
    1,136
    Thanks
    973
    Thanked 949 Times in 570 Posts


    Downloads
    5
    Uploads
    0
    Mentioned
    439 Post(s)
    Time Online
    55 d 7 h 17 m
    Avg. Time Online
    42 m
    Rep Power
    12
    4. Solve algebraically. what is the significance of the solution in terms of the graph of the two equations?
    3x-5y=12
    6y-10y=14

    I think in the second equation you're supposed to have an x somewhere in there...

  3. #3

    Join Date
    Dec 2011
    Gender
    Location
    United States
    Posts
    5,856
    Thanks
    1,493
    Thanked 2,146 Times in 1,216 Posts


    Downloads
    6
    Uploads
    0
    Mentioned
    1092 Post(s)
    Time Online
    42 d 18 h 30 m
    Avg. Time Online
    32 m
    Rep Power
    15
    @Aerandria yup, messed that up, edited. i need this done very sson guys. due in an hour.

  4. #4
    Ana's Avatar
    Join Date
    Mar 2012
    Gender
    Location
    No where :P
    Posts
    1,136
    Thanks
    973
    Thanked 949 Times in 570 Posts


    Downloads
    5
    Uploads
    0
    Mentioned
    439 Post(s)
    Time Online
    55 d 7 h 17 m
    Avg. Time Online
    42 m
    Rep Power
    12
    4. Solve algebraically. what is the significance of the solution in terms of the graph of the two equations?
    3x-5y=12
    6x-10y=14

    3x-5y=12
    x = (12+5y)/3

    6x-10y=14
    6[(12+5y)/3]-10y=14
    2(12+5y)-10y=14
    24+10y-10y=14
    24=14

    These is no solution for y (it cancels out), meaning these two lines are parallel

    ---------- Post added at 08:11 AM ---------- Previous post was at 08:09 AM ----------

    1. find a formula for f^-1(x) given f(x)=ln(2x-5)

    y=ln(2x-5)

    2x-5=e^y

    2x=e^y+5

    x=(e^y + 5)/2

    f^-1(x)=(e^x + 5)/2

    ---------- Post added at 08:13 AM ---------- Previous post was at 08:11 AM ----------

    2.given f(x)=x^3-4x^2-11x+30 (a)find the zeros and (b) write a linear factorization of the function.

    a) Zeroes (found through graphing): 5, -3, 2

    b) (x-5)(x+3)(x+2)

  5. #5

    Join Date
    Dec 2011
    Gender
    Location
    United States
    Posts
    5,856
    Thanks
    1,493
    Thanked 2,146 Times in 1,216 Posts


    Downloads
    6
    Uploads
    0
    Mentioned
    1092 Post(s)
    Time Online
    42 d 18 h 30 m
    Avg. Time Online
    32 m
    Rep Power
    15
    @Aerandria thank you are you planning to try any more or shall i rep now?

  6. #6
    Ana's Avatar
    Join Date
    Mar 2012
    Gender
    Location
    No where :P
    Posts
    1,136
    Thanks
    973
    Thanked 949 Times in 570 Posts


    Downloads
    5
    Uploads
    0
    Mentioned
    439 Post(s)
    Time Online
    55 d 7 h 17 m
    Avg. Time Online
    42 m
    Rep Power
    12
    I'm working on the last one ^^

  7. #7

    Join Date
    Dec 2011
    Gender
    Location
    United States
    Posts
    5,856
    Thanks
    1,493
    Thanked 2,146 Times in 1,216 Posts


    Downloads
    6
    Uploads
    0
    Mentioned
    1092 Post(s)
    Time Online
    42 d 18 h 30 m
    Avg. Time Online
    32 m
    Rep Power
    15
    alright thanks

  8. #8
    Ana's Avatar
    Join Date
    Mar 2012
    Gender
    Location
    No where :P
    Posts
    1,136
    Thanks
    973
    Thanked 949 Times in 570 Posts


    Downloads
    5
    Uploads
    0
    Mentioned
    439 Post(s)
    Time Online
    55 d 7 h 17 m
    Avg. Time Online
    42 m
    Rep Power
    12
    3.You are planning to make an open rectangular box from a 20 by 25in piece of cardboard by cutting congruent squares of side x from the corners and folding up the sides.

    (a) write a funtion V(x)for the volume of the box
    v(x)=x(20-2x)(25-2x)
    (b)what is the domain of V?
    0<x<10
    (c) Graph the function on your calculator and find the maximum volume
    I don't have a graphing calculator with me right now, but you can graph the line and then find the maximum
    (d) what are the dimmensions of the box yielding the maximum volume?
    Use the x value of the maximum as x in the volume equation, and it solve for the other two dimensions. X should be 3. something

  9. #9

    Join Date
    Dec 2011
    Gender
    Location
    United States
    Posts
    5,856
    Thanks
    1,493
    Thanked 2,146 Times in 1,216 Posts


    Downloads
    6
    Uploads
    0
    Mentioned
    1092 Post(s)
    Time Online
    42 d 18 h 30 m
    Avg. Time Online
    32 m
    Rep Power
    15
    repped thanks so much, i owe you 5 more

  10. #10
    Ana's Avatar
    Join Date
    Mar 2012
    Gender
    Location
    No where :P
    Posts
    1,136
    Thanks
    973
    Thanked 949 Times in 570 Posts


    Downloads
    5
    Uploads
    0
    Mentioned
    439 Post(s)
    Time Online
    55 d 7 h 17 m
    Avg. Time Online
    42 m
    Rep Power
    12
    Found an online graphing calculator
    3)
    (c) answer is 820.53
    (d) x = 3.68
    So the dimensions are 3.68 x 12.64 x 17.64

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •