Home
Class 12
MATHS
suppose D= |{:(a(1),,b(1),,c(1)),(a(2)...

suppose `D= |{:(a_(1),,b_(1),,c_(1)),(a_(2),,b_(2),,c_(2)),(a_(3),,b_(3),,c_(3)):}| ` and `Dprime= |{:(a_(1)+pb_(1),,b_(1)+qc_(1),,c_(1)+ra_(1)),(a_(2)+pb_(2),,b_(2)+qc_(2),,c_(2)+ra_(2)),(a_(3)+pb_(3),,b_(3)+qc_(3),,c_(3)+ra_(3)):}| `. Then

A

`D'=D`

B

`D'=D(1-pqr)`

C

`D=D(1+p+q+r)`

D

`D'=D(1+pqr)`

Text Solution

Verified by Experts

The correct Answer is:
D

`D' = |{:(a_(1)+pb_(1),,b_(1)+qc_(1),,c_(1)+rq_(1)),(a_(2)+pb_(2),,b_(2)+qc_(2),,c_(2)+ra_(2)),(a_(3)+pb_(3),,b_(3)+qc_(3),,c_(3)+ra_(3)):}|`
`=|{:(a_(1),,b_(1)+qc_(1),,c_(1)+rq_(1)),(a_(2),,b_(2)+qc_(2),,c_(2)+ra_(2)),(a_(3),,b_(3)+qc_(3),,c_(3)+ra_(3)):}|+ |{:(pb_(1),,b_(1)+qc_(1),,c_(1)+rq_(1)),(pb_(2),,b_(2)+qc_(2),,c_(2)+ra_(2)),(pb_(3),,b_(3)+qc_(3),,c_(3)+ra_(3)):}|`
In the first determinant apply `C_(3) to C_(3) -rC_(1)` and then
`C_(2) to C_(2)-qC_(3)`
In the second determinant teke p common from `C_(1)` and then apply
`C_(2) to C_(2)-C_(1)` Then take q common from `C_(2) ` and apply
`C_(3) to C_(3) -C_(2)` Finally taking r common from `C_(3)` we have finally `D'=(1+pqr ) D`
Promotional Banner

Topper's Solved these Questions

  • DETERMINANT

    CENGAGE PUBLICATION|Exercise Multiple Correct Answer|5 Videos
  • DIFFERENT PRODUCTS OF VECTORS AND THEIR GEOMETRICAL APPLICATIONS

    CENGAGE PUBLICATION|Exercise Multiple correct answers type|11 Videos

Similar Questions

Explore conceptually related problems

If the determinant of the matrix [(a_(1),b_(1),c_(1)),(a_(2),b_(2),c_(2)),(a_(3),b_(3),c_(3))] is denoted by D, then the determinant of the matrix [(a_(1)+3b_(1)-4c_(1),b_(1),4c_(1)),(a_(2)+3b_(2)-4c_(2),b_(2),4c_(2)),(a_(3)+3b_(3)-4c_(3),b_(3),4c_(3))] will be -

If x in R,a_(i),b_(i),c_(i) in R for i=1,2,3 and |{:(a_(1)+b_(1)x,a_(1)x+b_(1),c_(1)),(a_(2)+b_(2)x,a_(2)x+b_(2),c_(2)),(a_(3)+b_(3)x,a_(3)x+b_(3),c_(3)):}|=0 , then which of the following may be true ?

If Delta=|(a_1,b_1,c_1),(a_2,b_2,c_2),(a_3,b_3,c_3)| and Delta_1=|(a_1+pb_1,b_1+qc_1,c_1+ra_1),(a_2+pb_2,b_2+qc_2,c _2+ra_2),(a_3+pb_3,b_3+qc_3,c_3+ra_3)| then Delta_1=

Find the coordinates of the centriod of the triangle whose vertices are ( a_(1), b_(1), c_(1)) , (a_(2), b_(2), c_(2)) and (a_(3), b_(3), c_(3)) .

Applying vectors , show that (a_(1)b_(1)+a_(2)b_(2)+a_(3)b_(3))^(2)le (a_(1)^(2)+a_(2)^(2)+a_(3)^(2))(b_(1)^(2)+b_(2)^(2)+b_(3)^(2))

If a_(1), a_(2), a_(3), …., a_(n) are in H.P., prove that, a_(1)a_(2) + a_(2)a_(3) + a_(3)a_(4) +…+ a_(n-1)a_(n) = (n-1)a_(1)a_(n)

If a_(1), a_(2), a_(3),…, a_(2k) are in A.P., prove that a_(1)^(2) - a_(2)^(2) + a_(3)^(2) - a_(4)^(2) +…+a_(2k-1)^(2) - a_(2k)^(2) = (k)/(2k-1)(a_(1)^(2) - a_(2k)^(2)) .

Represent the following equations in matrix form: a_(1)x+b_(1)y+c_(1)z=k_(1) a_(2)x+b_(2)y+c_(2)z=k_(2) a_(3)x+b_(3)y+c_(3)z=k_(3)

If a_(1), a_(2), a_(3),…, a_(n) be in A.P. Show that, (1)/(a_(1)a_(2)) + (1)/(a_(2)a_(3)) +….+(1)/(a_(n-1)a_(n)) = (n-1)/(a_(1)a_(n))

CENGAGE PUBLICATION-DETERMINANTS-All Questions
  1. suppose D= |{:(a(1),,b(1),,c(1)),(a(2),,b(2),,c(2)),(a(3),,b(3),,c(3...

    Text Solution

    |

  2. If P = {1,2}, form set set P xx P xx P

    Text Solution

    |

  3. Statement 1: If b c+q r=c a+r p=a b+p q=-1, then |{:(ap ,a, p) ,(bq,...

    Text Solution

    |

  4. If f(theta)=|sinthetacosthetasinthetacosthetasinthetacosthetacosthetas...

    Text Solution

    |

  5. If f(theta)=|[sin^2A,cot A,1],[sin^2B,cotB,1],[sin^2C,cotC,1]| , then ...

    Text Solution

    |

  6. The roots of the equation |^x Cr^(n-1)Cr^(n-1)C(r-1)^(x+1)Cr^n Cr^n C(...

    Text Solution

    |

  7. Let Delta(x)=|[3,3x,3x^2+2a^2] , [3x, 3x^2+2a^2, 3x^3+6a^2x] , [3x^2+2...

    Text Solution

    |

  8. The determinant |(a^(2)+10,ab, ac),(ab, b^(2)+10, bc),(ac, bc, c^(2)...

    Text Solution

    |

  9. If f(x)=|[a,-1, 0],[a x, a,-1],[a x^2,a x, a]|,using properties of det...

    Text Solution

    |

  10. If (x)=|[x^2+4x-3 2x+4 13] [2x^2+5x-9 4x+5 26] [ 8x^2-6x+1 16 x-6 10...

    Text Solution

    |

  11. If |y z-x^2z x-y^2x y-z^2x z-y^2x y-z^2y z-x^2x y-z^2y z-x^2z x-y^2|=|...

    Text Solution

    |

  12. Let f(n)=|n n+1 n+2 ^n Pn^(n+1)P(n+1)^n Pn^n Cn^(n+1)C(n+1)^(n+2)C(n+2...

    Text Solution

    |

  13. If |[ x^n ,x^(n+2) ,x^(2n)],[1 ,x^a , a ],[x^(n+5),x^(a+6),x^(2n+5)]...

    Text Solution

    |

  14. Let x<1, then value of |[x^2+2, 2x+1 ,1],[ 2x+1,x+2, 1],[ 3, 3 ,1]| is...

    Text Solution

    |

  15. Find the number of real root of the equation |[0,x-a, x-b],[ x+a,0,x-...

    Text Solution

    |

  16. Value of |[x+y, z,z ],[x, y+z, x],[y, y, z+x]|, where x ,y ,z are nonz...

    Text Solution

    |

  17. If e^(itheta)=costheta+isintheta, find the value of |[1,e^(ipi//3),e...

    Text Solution

    |

  18. Which of the following is not the root of the equation |[x,-6,-1],[ 2,...

    Text Solution

    |

  19. If A,B,C are the angles of a non right angled triangle ABC. Then find ...

    Text Solution

    |

  20. Let f(x)=a(5)x^(5)+a(4)x^(4)+a(3)x^(3)+a(2)x^(2)+a(1)x, "where" a(i),s...

    Text Solution

    |

  21. Evaluate |(cosalphacosbeta,cosalpha sinbeta , - sin alpha),(-sin beta,...

    Text Solution

    |