Home
Class 12
MATHS
Value of the D=|(1/a,bc,a^(3)),(1/b,ca,b...

Value of the `D=|(1/a,bc,a^(3)),(1/b,ca,b^(3)),(1/c,ab,c^(3))|` is

A

0

B

`(a^(3)-1)(a^(6)-1)(a^(9)-1)`

C

`(a^(3)+1)(a^(6)+1)(a^(9)+1)`

D

`a^(15)-1`

Text Solution

AI Generated Solution

The correct Answer is:
To find the value of the determinant \( D = \begin{vmatrix} \frac{1}{a} & bc & a^3 \\ \frac{1}{b} & ca & b^3 \\ \frac{1}{c} & ab & c^3 \end{vmatrix} \), we will follow these steps: ### Step 1: Factor out common terms We can factor out \( \frac{1}{abc} \) from the first column. This gives us: \[ D = \frac{1}{abc} \begin{vmatrix} 1 & bc & a^3 \\ 1 & ca & b^3 \\ 1 & ab & c^3 \end{vmatrix} \] **Hint:** Look for common factors in the rows or columns to simplify the determinant. ### Step 2: Perform row operations Next, we can perform row operations to simplify the determinant. We can subtract the first row from the second and third rows: \[ D = \frac{1}{abc} \begin{vmatrix} 1 & bc & a^3 \\ 0 & ca - bc & b^3 - a^3 \\ 0 & ab - bc & c^3 - a^3 \end{vmatrix} \] **Hint:** Row operations can help eliminate variables and simplify the determinant. ### Step 3: Factor out common terms from the second and third rows Now, we can factor out \( (ca - bc) \) from the second row and \( (ab - bc) \) from the third row: \[ D = \frac{1}{abc} \cdot (ca - bc) \cdot (ab - bc) \begin{vmatrix} 1 & bc & a^3 \\ 0 & 1 & \frac{b^3 - a^3}{ca - bc} \\ 0 & 1 & \frac{c^3 - a^3}{ab - bc} \end{vmatrix} \] **Hint:** Look for patterns in the rows or columns that can be factored out. ### Step 4: Analyze the determinant Now, we can see that the second and third rows are identical if \( b^3 - a^3 \) and \( c^3 - a^3 \) are equal. This means that the determinant will equal zero if two rows are identical: \[ D = 0 \] **Hint:** If two rows or columns of a determinant are identical, the determinant is zero. ### Conclusion Thus, the value of the determinant \( D \) is: \[ \boxed{0} \]
Promotional Banner

Topper's Solved these Questions

  • DETERMINANTS

    MOTION|Exercise EXERCISE-2 (LEVEL-II)|6 Videos
  • DETERMINANTS

    MOTION|Exercise EXERCISE-3|36 Videos
  • DETERMINANTS

    MOTION|Exercise EXERCISE-1|13 Videos
  • DEFINITE INTEGRATION

    MOTION|Exercise EXERCISE -4 LEVEL-II|33 Videos
  • DIFFERENTIABILITY

    MOTION|Exercise Exercise - 4 | Level-I Previous Year | JEE Main|15 Videos

Similar Questions

Explore conceptually related problems

What is the value of the determinant |(1,bc,a(b+c)),(1,ca,b(c+a)),(1,ab,c(a+b))| ?

The value of the determinant |{:(1,bc,a(b+c)),(1,ca,b(a+c)),(1, ab,c(a+b)):}| doesn't depend on

The value of |(a,a^(2) - bc,1),(b,b^(2) - ca,1),(c,c^(2) - ab,1)| , is

|[1,bc,a(b+c)],[1,ca,b(c+a)],[1,ab,c(a+b)]|=0

The value of the determinant |(1,a,a^2-bc),(1,b,b^2-ca),(1,c,c^2-ab)| is (A) (a+b+c),(a^2+b^2+c^2) (B) a^3+b^3+c^3-3abc (C) (a-b)(b-c)(c-a) (D) 0

The value of the determinant |{:(1,a, a^(2)-bc),(1, b, b^(2)-ca),(1, c, c^(2)-ab):}| is…..

If bc+ca+ab=18 and |(1,a^(2),a^(3)),(1,b^(2),b^(3)),(1,c^(2),c^(3))|=lamda|(1,1,1),(a,b,c),(a^(2),b^(2),c^(2))| the value of lamda is

Without expanding the determinant , prove that |{:(a, a^(2),bc),(b,b^(2),ca),(c,c^(2),ab):}|=|{:(1,a^(2),a^(3)),(1,b^(2),b^(3)),(1,c^(2),c^(3)):}|