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Homework Help: Having some trouble interpretting several problems! (link fixed)

  1. Sep 11, 2004 #1
    HI, i previously posted this message but i think someone took it off because my link doesnt work. Try it now. Copy and paste this if the link don't work

    this:http://www.freewebs.com/easystyle4747/math1%20copy.jpg [Broken]

    thats the link to some questions that I don't quite understand. The thing is, I'm horrible at math terminology, so i have no idea what those things are even asking me to do. My teacher spent all of class explaing the second half of my homework and so i dont know how to do these problems. I have much more problems than those, but those are one of each type. You don't have to give me the answer, infact, i don't want you to. Someone just help me explain those problems as thoroughly as possible. And plz dont use too much math terminology because i don't really understand too much of it.
    Last edited by a moderator: May 1, 2017
  2. jcsd
  3. Sep 11, 2004 #2
    i duno wat is wrong, but if u click the link it takes you right back here. U have to copy and paste it for it to work.
  4. Sep 11, 2004 #3
    Link works if you copy and paste.

    For 66: find equations for p and h that have x as the variable
    70: You can deduce the x-coordinates of the points of intersection of the rectangle and semicircle from the diagram. From there, you should be able to find the length of the short side of the rectangle, and thus calculate the area.
    73: Hint: you know speed = distance/time.
    74: Visualize the circle (disk) formed by the line segment when it is revolved. You know that A = πr². So you need to find the length of the radius in terms of x...
  5. Sep 11, 2004 #4
    OK, i still have some issues with each of these, and like i said, i my teacher hasnt explained any of these yet.

    66. So i assume u mean to find the equation for the line p and h right? But how do you do that? how do u find the equation between that point on the curved line and the x-axis?
    70. Well, i can easily find the area in numbers. But express as a function of x? What do i needa do?
    73. I still dunt understand the figure. Are we supposed to find the shortest point from the start to destination or are we suppose to follow the dotted path they give us? And, again, the express as function of x thing again. How does that kick in?
    74. Again, how do you solve the distance between a point on the curve and the x-axis (aka in this problem, the radius) ?

    Thanks for the tips, but plz enlighten me some more.
  6. Sep 12, 2004 #5
    66: OK, find the coordinates of the point of intersection between h and the circle in terms of x only (hint: if the x-coordinate is x, what is the y coordinate -- use the equation)
    70: Sorry, I was wrong here. Use the same approach as 66. The x-coordinate of the point of intersection is given to you as x...what is the y-coordinate? You should be able to get the area from there.
    73: You follow the hypothenus of each triangle. Find the length of each hypothenus using Pythagorus. For each segment, you have the speed and the distance, so you should be able to find time (in terms of x because you used lengths in terms of x to calculate the length of each hypothenus).
    74: You must understand that the y-coordinate of a point on a function is its vertical distance fromt the x-axis. If the coordinates of a point are (x, y), use the same technique as 66 and 70 to find the y-coordinate (from eqn.) and use that to find the area of the disc.
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