3-d

the number of straight lines that are equally inclined to the three dimensional co-ordinate axis ,is

6 Answers

ans is 4

but the direction ratios can be arranged in the folowing ways :-

1,1,1
1,1,-1
1,-1,1
-1,1,1
1,-1,-1
-1,1,-1
-1,-1,1 and
1,1,1.
where am i going wrong?? :(

the lines with direction cosines 1,1,1 is the same as -1,-1,-1 extended backwards so diagonally opposite octants contain the same same line , hence 4

oh, yes.. thanx,,.. :)

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