Home
Class 12
MATHS
The value of the determinant |(1,a,a^2-b...

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

Text Solution

AI Generated Solution

The correct Answer is:
To find the value of the determinant \[ \Delta = \begin{vmatrix} 1 & a & a^2 - bc \\ 1 & b & b^2 - ca \\ 1 & c & c^2 - ab \end{vmatrix} \] we will perform some row operations to simplify the determinant. ### Step 1: Subtract the first row from the second and third rows We will apply the row operations \( R_2 \leftarrow R_2 - R_1 \) and \( R_3 \leftarrow R_3 - R_1 \): \[ \Delta = \begin{vmatrix} 1 & a & a^2 - bc \\ 0 & b - a & b^2 - ca - (a^2 - bc) \\ 0 & c - a & c^2 - ab - (a^2 - bc) \end{vmatrix} \] Calculating the entries in the second and third rows: - For \( R_2 \): \[ b^2 - ca - (a^2 - bc) = b^2 - ca - a^2 + bc = b^2 - a^2 + bc - ca \] - For \( R_3 \): \[ c^2 - ab - (a^2 - bc) = c^2 - ab - a^2 + bc = c^2 - a^2 + bc - ab \] Thus, we have: \[ \Delta = \begin{vmatrix} 1 & a & a^2 - bc \\ 0 & b - a & b^2 - a^2 + bc - ca \\ 0 & c - a & c^2 - a^2 + bc - ab \end{vmatrix} \] ### Step 2: Factor out common terms Now we can factor out \( (b - a) \) and \( (c - a) \) from the second and third rows respectively: \[ \Delta = (b - a)(c - a) \begin{vmatrix} 1 & a & a^2 - bc \\ 0 & 1 & \frac{b^2 - a^2 + bc - ca}{b - a} \\ 0 & 1 & \frac{c^2 - a^2 + bc - ab}{c - a} \end{vmatrix} \] ### Step 3: Simplify the determinant Now we can simplify the determinant further. The new determinant is: \[ \Delta = (b - a)(c - a) \begin{vmatrix} 1 & a & a^2 - bc \\ 0 & 1 & \frac{(b - a)(b + a) + bc - ca}{b - a} \\ 0 & 1 & \frac{(c - a)(c + a) + bc - ab}{c - a} \end{vmatrix} \] ### Step 4: Final determinant evaluation Since we have two identical rows (the second and third rows are now multiples of each other), the determinant evaluates to zero: \[ \Delta = 0 \] ### Conclusion Thus, the value of the determinant is: \[ \boxed{0} \]
Doubtnut Promotions Banner Mobile Dark
|

Topper's Solved these Questions

  • MATRICES AND DETERMINANTS

    VMC MODULES ENGLISH|Exercise JEE MAIN ARCHIVE|92 Videos
  • JEE MAIN REVISON TEST-23

    VMC MODULES ENGLISH|Exercise MATHEMATICS (SECTION 2)|5 Videos
  • MOCK TEST 1

    VMC MODULES ENGLISH|Exercise PART III : MATHEMATICS (SECTION-2)|10 Videos

Similar Questions

Explore conceptually related problems

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

Value of |(1,a,a^2),(1,b,b^2),(1,c,c^2)| is (A) (a-b)(b-c)(c-a) (B) (a^2-b^2)(b^2-c^2)(c^2-a^2) (C) (a-b+c)(b-c+a)(c+a-b) (D) none of these

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

Prove: |a^3 2a b^3 2b c^3 2c|=2(a-b)(b-c)(c-a(a+b+c)

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)|

(a-b)^3 + (b-c)^3 + (c-a)^3=? (a) (a+b+c)(a^2+b^2+c^2-ab-bc-ac) (b) 3(a-b)(b-c)(c-a) (c) (a-b)(b-c)(c-a) (d)none of these

By using properties of determinants. Show that: (i) |[1,a, a^2],[ 1,b,b^2],[ 1,c,c^2]|=(a-b)(b-c)(c-a) (ii) |[1, 1, 1],[a, b, c],[ a^3,b^3,c^3]|=(a-b)(b-c)(c-a)(a+b+c)

Prove that |{:(a,,a^(2),,bc),(b ,,b^(2),,ac),( c,,c^(2),,ab):}| = |{:(1,,1,,1),(a^(2) ,,b^(2),,c^(2)),( a^(3),, b^(3),,c^(3)):}|

Prove that a^3+b^3+c^3-3abc=1/2(a+b+c){(a-b)^2+(b-c)^2+(c-a)^2}

Prove that : |{:(a,b,c),(a^(2),b^(2),c^(2)),(bc,ca,ab):}|=(a-b)(b-c)(c-a)(ab+bc+ca)