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3-Dimensional Geometery

3-Dimensional Geometery

by Chandni Bhatia -
Number of replies: 2
If variable plane at a constant distance p from the origin meets the coordinate axes in points A,B and C respectively.Through these points,planes are drawn parallel to the coordinate planes.Then, show that the locus of point of intersection  is    x-2 +  y-2 + z-2 = p-2.
In reply to Chandni Bhatia

Re: 3-Dimensional Geometery

by Manoj Tirukodi Radhakrishn -

Hey Chandni you should be knowing that the intercept form of a plane is (x/a)+(y/b)+(z/c)=1. if you need a proof, see that the points (a,0,0);(0,b,0);(0,0,c) satisfy the equation and a smart girl like you should be knowing that i can have only 1 plane passing through three non-collinear points. So, the point of intersection of the planes x=a;y=b;z=c is obviously (a,b,c) and now you know that the equation for the distance of a point from a plane is same as what we had studied in 2-D.

So distance from the origin is.

[mod(0+0+0-1)]/sqrt[(1/a2)+(1/b2)+(1/c2)]=p

as the required locus is that of (a,b,c), replace (a,b,c) with (x,y,z) you see that you have the answer

            Manojevilbig grinwink