pliz help me to plot the three dimensions accurately by using the graph show it step by step,eg.(-5,4,4)

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- Feb 12th 2007, 08:17 PM #1

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- Feb 13th 2007, 10:08 PM #2
Hello,

I'm not quite certain what you don't understand.

First you need a coordinate-system. You have given a point in 3-D-space. So I assume that you should use a coordinate-system with 3 axes. For convenience I assume the these axes are perpendicular to each other.

Now you have to determine how you want to draw these axes:

i)Put the y- and the z-axis into the drawing plane. Then the x-axis has to be reduced bei a constant faktor. 1/2*√(2) ≈ 0.707 is not a bad choice. Then you can construct a cuboid(?) with the origin and your given point at opposite sides auf a diagonal. (see attachment)

ii)Only the z-axis is in the drawing plane. All axes are scaled equal. Then you have an isometric coordinate-system in which you can very easily construct the cuboid to locate the given point. (see attachment)

EB

- Feb 14th 2007, 06:38 AM #3

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Hello, zasi!

pliz help me to plot the three dimensions accurately

by using the graph. Show it step by step: e.g. P(-5,4,4)

If you've never done this before, you need to know some basics.

We take our familiar xy-plane and "lay it on the floor".

Then the z-axis will run up and down.

The first "octant" (where all three coordinates are positive) looks like this:Code:z | | | | | | * - - - - - - - y / / / / / x

It may help the visualization if I draw in the "walls" and "floor".Code:z * - - - - - - * /| | / | | / | | / | | * | | | * - - - - - - * y | / / | / / | / / |/ / *- - - - - - -* x

I remind you that the z-axis extends below the "floor"

. . (that is where z is negative)

that the y-axis extends to the left of the "left wall",

and the x-axis extends behind the "back wall".

To plot P(-5, 4, 4), note what it says:

. . x = -5, y = 4, z = 4.

Starting at the origin, we move -5 in the x-direction

. . (that's 5 units*behind*the "back wall"),

then move +4 in the y-direction

. . (that's 4 units to the right),

then move +4 in the z-direction

. . (that's 4 units up).

And*there*is point P(-5, 4, 4).

It's difficult to draw (or type) a three-dimensional situation

. . on a two-dimensional screen, but I'll try.Code:z P | o | : | :4 | : | * - - - * | / 4 | /-5 |/ * - - - - - - - y / / / / / x

Think of directions to your friend's new apartment.

You start at a mutually-agreed location, say, City Hall.

You are told to drive 5 blocks north,

. . then and 4 blocks east, locating the building,

. . then take the elevator to the fourth floor.

And*there*is his/her apartment.