If the system of linear equations 2 x + 2 a y + a z = 0 2 x + 3 b y + b z = 0 2 x + 4 c y + c z = 0 , where…

If the system of linear equations
2x+2ay+az=0
2x+3by+bz=0
2x+4cy+cz=0,
where a,b,cR are non-zero and distinct; has a non-zero solution, then
  1. 1a,1b,1c are in A.P.
  2. a,b,c are in G.P.
  3. a+b+c=0
  4. a,b,c are in A.P.

Solution

22aa23bb24cc=0
12aa13bb14cc=0
3bc-4bc-2ac-4ac+2ab-3ab=0
-bc+2ac-ab=0
ab+bc=2ac
a,b,c in H.P.
1a,1b,1c in A.P.

Asked in: JEE Main 2020 (07 Jan Shift 1)

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