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Question: Answered & Verified by Expert
If [x] denotes the greatest integer x, then the system of linear equations [sinθ]x+[-cosθ]y=0[cotθ]x+y=0
MathematicsDeterminantsJEE Main
Options:
  • A has a unique solution if θπ2,2π3π,7π6
  • B have infinitely many solution if  θπ2,2π3π,7π6
  • C has a unique if θπ2,2π3 and have infinitely many solutions if θπ,7π6
  • D have infinitely many solutions if θπ2,2π3 and has a unique solution if θπ,7π6
Solution:
2253 Upvotes Verified Answer
The correct answer is: have infinitely many solutions if θπ2,2π3 and has a unique solution if θπ,7π6

sinθx+-cosθy=0  and cosθx+y=0  for infinite many solution
sinθ-cosθcotθ 1=0
i.e. sinθ= -cosθ  cotθ   ...i
when θπ2, 2π3 then sinθ0, 12  sinθ=0 and -cosθ0, 12  -cosθ=0 and  

cotθ-13, 0  cotθ=-1
When θπ, 7π6 then sinθ-12, 0  sinθ=-1 and -cosθ32, 1 -cosθ=0 and 
cotθ3,    cotθ2, 3, 4,...
When θπ2, 2π3  then the equation i satisfied therefore infinitely many solution.
When θπ, 7π6  then the equation i not satisfied therefore unique solution.

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