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Sunne1111
Newbie
Joined: 29 May 2004 Posts: 2
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Posted: 29 May 2004 09:27:02 pm Post subject: |
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Someone help me! My teacher gave me a project for my Hnrs. Alg. II class on conic sections. But I'm sooo bad with my TI. I have noooo idea what to do. I need to draw a picture with: 1) parabola 2)Ellipse (up&down) 3)Ellipse (side2side) 4)hyperbola.
I decided to try to make a hamburger. But I cant even get the first parabola in the DrawF program correct. What do I do? Can someone PLEASE PLEASE PLEASE help me! |
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Jeremiah Walgren General Operations Director
Know-It-All
Joined: 24 May 2003 Posts: 1937
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Posted: 29 May 2004 10:17:58 pm Post subject: |
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What have you got so far? |
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Ray Kremer
Member
Joined: 16 Feb 2004 Posts: 237
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Posted: 30 May 2004 02:03:51 am Post subject: |
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Gah. Why is it that teachers everywhere use this stupid assignment, especially without giving the students the necessary instruction first? |
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Arcane Wizard `semi-hippie`
Super Elite (Last Title)
Joined: 02 Jun 2003 Posts: 8993
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Posted: 30 May 2004 04:56:59 am Post subject: |
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Moving functions: (or whatever you call the actually graphed line in english)
To move the entire function horizontally:
Replace X with (X+A)
A can be any number and defines by how much you move it.
To move the entire function vertically:
Add a number, or add the rest of the function to a number. R+B
R being the rest of the function, B being any number.
To squeeze the function horizontally:
Change X to (CX)
C being any number
To stretch the function horizontally:
Change X to (X/D)
D being any number
To squeeze the function vertically:
Multiply the entire function by E
E being any number
To stretch the function vertically:
Devide the entire function by F
F being any number
Examples:
We have the function X² + X
Move to the left by 3: (X+3)² + (X+3)
Move to right by 6: (X-6)² + (X-6)
Move up by 10: X² + X + 10 or 10 + X² + X
Move down by 4: X² + X - 4
Horizontal Squeeze by 6: (6X)² + (6X)
Horizontal Stretch by 7: (X/7)² + (X/7)
Vertical Squeeze by 12: (X² + X)/12
Vertical Stretch by 8: 8(X² + X)
Now, combine and use that to move and change the functions so you eventually have a pic, kind of like sculpturing. : )
I think there may be some functions where it doesn't work too well though, but it's always worked for all the functions I've encountered in my life and that includes hyperbola and those other ones you mentioned.
And it's funny how I had to think of that myself instead of getting it at math.
Last edited by Guest on 30 May 2004 04:58:38 am; edited 1 time in total |
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Jeremiah Walgren General Operations Director
Know-It-All
Joined: 24 May 2003 Posts: 1937
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Posted: 30 May 2004 03:28:14 pm Post subject: |
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Ray Kremer wrote: Gah. Why is it that teachers everywhere use this stupid assignment, especially without giving the students the necessary instruction first?
I received a similar assignment, if memory serves correctly. Except I had to do it on paper... |
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Sunne1111
Newbie
Joined: 29 May 2004 Posts: 2
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Posted: 30 May 2004 09:04:29 pm Post subject: |
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Arcane Wizard,
c, I understand how to graph eqn's., just not how to get it myself. Does anyone have a picture drawn already that could just give me the eqn's? I'm so desperate that I'll pay someone if the picture works out. Neone that has a solution can email me at [email=Sunne1111@yahoo.com]Sunne1111@yahoo.com[/email] to make it easier to communicate.
Thanks a lot!
Distressed... |
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Arcane Wizard `semi-hippie`
Super Elite (Last Title)
Joined: 02 Jun 2003 Posts: 8993
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Posted: 31 May 2004 06:14:08 am Post subject: |
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Turn your calc on
Press Y=
Type in the equations
Press Trace
Go back to Y= and change the equations, then go back to Trace and repeat this step untill you have the pic you want.
Press 2nd and then prgm, then press left and enter. Type in a number and press enter again. Now you have the pic stored so you can go and do other things.
To show the pic, clear the graphscreen (2nd, prgm, enter) and type:
2nd, prgm, left, down, enter, the number you typed previsouly, and enter. |
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X1011 10100111001
Active Member
Joined: 14 Nov 2003 Posts: 657
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Posted: 31 May 2004 12:25:45 pm Post subject: |
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Wouldn't it be better to store a GBD so he can have the equations stored?
Anyways, you can put points you want in lists and use QuadReg to get an equation. |
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DarkerLine ceci n'est pas une |
Super Elite (Last Title)
Joined: 04 Nov 2003 Posts: 8328
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Posted: 31 May 2004 02:08:37 pm Post subject: |
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You'd have a problem with circles and ellipses because they aren't functions. |
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Arcane Wizard `semi-hippie`
Super Elite (Last Title)
Joined: 02 Jun 2003 Posts: 8993
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Posted: 31 May 2004 05:24:56 pm Post subject: |
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Not quite, you can use radian mode and cos/sin X. |
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Jeremiah Walgren General Operations Director
Know-It-All
Joined: 24 May 2003 Posts: 1937
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Posted: 31 May 2004 06:17:50 pm Post subject: |
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Quote: Wouldn't it be better to store a GBD so he can have the equations stored?
*GDB.
Or there's the good ol' way of writing them down... |
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X1011 10100111001
Active Member
Joined: 14 Nov 2003 Posts: 657
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Posted: 31 May 2004 08:09:23 pm Post subject: |
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Sir Robin wrote: You'd have a problem with circles and ellipses because they aren't functions.
Circles are functions, you just have to solve for y, and get the square root to be positive and negitive
Y={1,-1}sqrt(R²-X²) |
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Ray Kremer
Member
Joined: 16 Feb 2004 Posts: 237
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Posted: 01 Jun 2004 12:47:37 am Post subject: |
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Sir Robin wrote: You'd have a problem with circles and ellipses because they aren't functions.
Well, the top half is one function and the bottom half is another function. |
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leofox INF student
Super Elite (Last Title)
Joined: 11 Apr 2004 Posts: 3562
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Posted: 01 Jun 2004 08:00:52 am Post subject: |
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Ray Kremer wrote: Sir Robin wrote: You'd have a problem with circles and ellipses because they aren't functions.
Well, the top half is one function and the bottom half is another function.
there always stays a little empty bit near Y=0, so it's no full circle. |
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Jeremiah Walgren General Operations Director
Know-It-All
Joined: 24 May 2003 Posts: 1937
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Posted: 01 Jun 2004 09:47:35 am Post subject: |
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Quote: there always stays a little empty bit near Y=0, so it's no full circle.
I think they can live with that. |
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X1011 10100111001
Active Member
Joined: 14 Nov 2003 Posts: 657
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Posted: 01 Jun 2004 03:42:35 pm Post subject: |
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leofox wrote: there always stays a little empty bit near Y=0, so it's no full circle.
i saw no empty bit |
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sgm
Calc Guru
Joined: 04 Sep 2003 Posts: 1265
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Posted: 01 Jun 2004 04:35:56 pm Post subject: |
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Use parametric graphing.
Circle:
x_t = a · cos t
y_t = a · sin t
Ellipse:
x_t = a · cos t
y_t = b · sin t
Parabola:
x_t = a · t^2
y_t = 2 · a · t |
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Jeremiah Walgren General Operations Director
Know-It-All
Joined: 24 May 2003 Posts: 1937
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Posted: 01 Jun 2004 05:39:30 pm Post subject: |
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X1011 wrote: leofox wrote: there always stays a little empty bit near Y=0, so it's no full circle.
i saw no empty bit
You need to zoom in closer, I'm guessing. |
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Ray Kremer
Member
Joined: 16 Feb 2004 Posts: 237
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Posted: 02 Jun 2004 02:45:35 am Post subject: |
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leofox wrote: there always stays a little empty bit near Y=0, so it's no full circle.
That depends entirely on the window settings. If the x-intercepts of the circle (with its center on the x-axis) fall inbetween two pixels, there will be an apparent gap. If the x-intercepts fall right on pixels, there is no gap. |
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leofox INF student
Super Elite (Last Title)
Joined: 11 Apr 2004 Posts: 3562
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Posted: 02 Jun 2004 08:15:10 am Post subject: |
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Ray Kremer wrote: leofox wrote: there always stays a little empty bit near Y=0, so it's no full circle.
That depends entirely on the window settings. If the x-intercepts of the circle (with its center on the x-axis) fall inbetween two pixels, there will be an apparent gap. If the x-intercepts fall right on pixels, there is no gap.
that would mean there IS a gap, but it's just invisible. |
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