Home
Class 12
MATHS
|((a^x+a^(-x))^2,(a^x-a^(-x))^(2),1),((b...

`|((a^x+a^(-x))^2,(a^x-a^(-x))^(2),1),((b^x+b^(-x))^2,(b^x-b^(-x))^(2),1),((c^x+c^(-x))^2,(c^x-c^(-x))^(2),1)|` =

A

0

B

abc

C

2abc

D

`a^2b^2c^2`

Text Solution

AI Generated Solution

The correct Answer is:
To solve the determinant \[ D = \begin{vmatrix} (a^x + a^{-x})^2 & (a^x - a^{-x})^2 & 1 \\ (b^x + b^{-x})^2 & (b^x - b^{-x})^2 & 1 \\ (c^x + c^{-x})^2 & (c^x - c^{-x})^2 & 1 \end{vmatrix} \] we will simplify the elements of the determinant step by step. ### Step 1: Simplify the first column The first column consists of the terms \((a^x + a^{-x})^2\), \((b^x + b^{-x})^2\), and \((c^x + c^{-x})^2\). Using the identity \((u + v)^2 = u^2 + v^2 + 2uv\), we can expand: \[ (a^x + a^{-x})^2 = a^{2x} + a^{-2x} + 2 \] \[ (b^x + b^{-x})^2 = b^{2x} + b^{-2x} + 2 \] \[ (c^x + c^{-x})^2 = c^{2x} + c^{-2x} + 2 \] Thus, the first column becomes: \[ \begin{pmatrix} a^{2x} + a^{-2x} + 2 \\ b^{2x} + b^{-2x} + 2 \\ c^{2x} + c^{-2x} + 2 \end{pmatrix} \] ### Step 2: Simplify the second column Now, we simplify the second column which consists of \((a^x - a^{-x})^2\), \((b^x - b^{-x})^2\), and \((c^x - c^{-x})^2\). Using the identity \((u - v)^2 = u^2 + v^2 - 2uv\), we can expand: \[ (a^x - a^{-x})^2 = a^{2x} + a^{-2x} - 2 \] \[ (b^x - b^{-x})^2 = b^{2x} + b^{-2x} - 2 \] \[ (c^x - c^{-x})^2 = c^{2x} + c^{-2x} - 2 \] Thus, the second column becomes: \[ \begin{pmatrix} a^{2x} + a^{-2x} - 2 \\ b^{2x} + b^{-2x} - 2 \\ c^{2x} + c^{-2x} - 2 \end{pmatrix} \] ### Step 3: Rewrite the determinant Now we can rewrite the determinant \(D\): \[ D = \begin{vmatrix} a^{2x} + a^{-2x} + 2 & a^{2x} + a^{-2x} - 2 & 1 \\ b^{2x} + b^{-2x} + 2 & b^{2x} + b^{-2x} - 2 & 1 \\ c^{2x} + c^{-2x} + 2 & c^{2x} + c^{-2x} - 2 & 1 \end{vmatrix} \] ### Step 4: Perform column operations Now, we can perform the column operation \(C_1 \rightarrow C_1 - C_2\): \[ D = \begin{vmatrix} 4 & 0 & 1 \\ 4 & 0 & 1 \\ 4 & 0 & 1 \end{vmatrix} \] ### Step 5: Evaluate the determinant Notice that the first two columns are proportional (each row in the first column is a multiple of the corresponding row in the second column). Thus, the determinant evaluates to: \[ D = 0 \] ### Final Answer The value of the determinant is: \[ \boxed{0} \]
Promotional Banner

Topper's Solved these Questions

  • DETERMINANTS

    ML KHANNA|Exercise MISCELLANEOUS EXERCISE |1 Videos
  • DEFINITE INTEGRAL

    ML KHANNA|Exercise Miscellaneous Questions (Assertion/Reason)|1 Videos
  • DIFFERENTIAL EQUATIONS

    ML KHANNA|Exercise MISCELLANEOUS EXERCISE (Matching Entries) |2 Videos

Similar Questions

Explore conceptually related problems

If a,b,c>0 and x,y,z in R then |[(a^x+a^(-x))^2, (a^x-a^(-x))^2, 1] , [(b^y+b^(-y))^2, (b^y-b^(-y))^2, 1], [(c^z+c^(-z))^2, (c^z-c^(-z))^2, 1]|=

If a, b,c> 0 and x,y,z in R then the determinant: |((a^x+a^-x)^2,(a^x-a^-x)^2,1),((b^y+b^-y)^2,(b^y-b^-y)^2,1),((c^z+c^-z)^2,(c^z-c^-z)^2,1)| is equal to

((x^(a))/(x^(-b)))^(a^(2)-ab+b^(2))times((x^(b))/(x^(-c)))^(b^(2)-bc+c^(2))times((x^(c))/(x^(-a)))^(c^(2)-ca+a^(2))

Prove that: ((x^(a+b))^(2)(x^(b+c))^(2)(x^(c+a))^(2))/((x^(a)x^(b)x^(c))^(4))

Let P(x)=((x-a)(x-b))/((c-a)(c-b))c^(2)+((x-b)(x-c))/((a-b)(a-c))a^(2)+((x-c)(x-a))/((b-c)(b-a))b^(2) Prove that P(x) has the property that P(y)=y^(2) for all y in R .

Show that: (x^(a(b-c)))/(x^(b(a-c)))-:((x^(b))/(x^(a)))^(c)=1((x^(a+b))(x^(b+c))^(2)(x^(c+a))^(2))/((x^(a)x^(b)x^(c))^(4))=1

ML KHANNA-DETERMINANTS -Self Assessment Test
  1. If a != b != c, are value of x which satisfies the equation |(0,x -a...

    Text Solution

    |

  2. |(b+c,a,a),(b,c+a,b),(c,c,a+b)|=

    Text Solution

    |

  3. |(1,1,1),(a,b,c),(a^3,b^3,c^3)|=

    Text Solution

    |

  4. |(1/a,a^2,bc),(1/b,b^2,ca),(1/c,c^2,ab)|=

    Text Solution

    |

  5. If x=-9 is a root of |(x,3,7),(2,x,2),(7,6,x)|=0 then other two roots ...

    Text Solution

    |

  6. The solution of the equation |(x,2,-1),(2,5,x),(-1,2,x)| = 0 are

    Text Solution

    |

  7. The roots of the equation |(0,x,16),(x,5,7),(0,9,x)| = 0 are

    Text Solution

    |

  8. |(a+b,b+c,c+a),(b+c,c+a,a+b),(c+a,a+b,b+c)|=k|(a,b,c),(b,c,a),(c,a,b)|...

    Text Solution

    |

  9. A root of the equation |(3-x,-6,3),(-6,3-x,3),(3,3,-6-x)| = 0

    Text Solution

    |

  10. If |(-a^2,ab,ac),(ab,-b^2,bc),(ac,bc,-c^2)|=ka^2b^2c^2 , then k =

    Text Solution

    |

  11. If omega!=1 is a cube root of unity and Delta=|(x+omega^(2),omega,1)...

    Text Solution

    |

  12. |((a^x+a^(-x))^2,(a^x-a^(-x))^(2),1),((b^x+b^(-x))^2,(b^x-b^(-x))^(2),...

    Text Solution

    |

  13. The number of values of k which the linear equations 4x+ky+2z=0 kx...

    Text Solution

    |

  14. The value of k for which the set of equationsx + ky + 3z=0, 3x + ky – ...

    Text Solution

    |

  15. If x + y +z=0, 4x+3y -z=0 and 3x + 5y +3z=0 is the given system of equ...

    Text Solution

    |

  16. The system of equations x + y + z=2, 3x – y +2z=6 and 3x + y +z=-18 ha...

    Text Solution

    |

  17. The system of equations x+y+z=6, x+2y + 3z= 10, x+2y + lamdaz=mu has n...

    Text Solution

    |

  18. The system of linear equations x1 + 2x2 + x3 = 3, 2x1 + 3x2 + x3 = 3...

    Text Solution

    |

  19. Let a,b,c be such that b(a+c) ne 0 . If |(a,a+1,a-1),(-b,b+1,b-1),(c...

    Text Solution

    |