Most Important Selected Qs for JEE AdvancedMathematicsDeterminants
System of equation aligned & x+3 y+2 z=6 & x+ y+2 z=7 & x+3 y+2 z= has aligned
Options
- AUnique solution if =2, 6
- BInfinitely many solution if =4, =6
- CNo solution if =5, =7
- DNo solution if =3, =5
Correct answer
D. No solution if =3, =5
Step-by-step solution
x+3 y+2 z=6 ....(i) x+ y+2 z=7 ....(ii) x+3 y+2 z= ....(iii) (A) If =2 , then D=0 , therefore unique solution is not possible (B) If =4, =6 aligned & x+3 y=6-2 z & x+4 y=7-2 z aligned y=1 and x=3-2 z Substituting in equation (iii) 3-2 z+3+2 z=6 is satisfied infinite solutions (C) =5, =7 consider equation (ii) and (iii) aligned & x+5 y=7-2 z & x+3 y=7-2 z aligned y=0, x=7-2 z are solution sub. in (i) 7-2 z+2 z=6 does not satisfy no solution (D) if =3, =5 then equation (i) and (ii) have no solution no solution