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If bc+ca+ab=18 and |(1,a^(2),a^(3)),(...

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

A

`-1`

B

0

C

9

D

18

Text Solution

AI Generated Solution

The correct Answer is:
To solve the given problem step by step, we will start with the determinants provided and use properties of determinants to find the value of \(\lambda\). ### Step 1: Write down the determinants We have two determinants given in the problem: 1. \( D_1 = \begin{vmatrix} 1 & a^2 & a^3 \\ 1 & b^2 & b^3 \\ 1 & c^2 & c^3 \end{vmatrix} \) 2. \( D_2 = \begin{vmatrix} 1 & 1 & 1 \\ a & b & c \\ a^2 & b^2 & c^2 \end{vmatrix} \) ### Step 2: Evaluate \(D_1\) The determinant \(D_1\) can be evaluated using the formula for determinants of the form: \[ \begin{vmatrix} 1 & x_1 & x_1^2 \\ 1 & x_2 & x_2^2 \\ 1 & x_3 & x_3^2 \end{vmatrix} = (x_1 - x_2)(x_2 - x_3)(x_3 - x_1) \] In our case, we have \(x_1 = a\), \(x_2 = b\), and \(x_3 = c\). Therefore: \[ D_1 = (a - b)(b - c)(c - a) \] ### Step 3: Evaluate \(D_2\) The determinant \(D_2\) can also be evaluated similarly: \[ D_2 = \begin{vmatrix} 1 & 1 & 1 \\ a & b & c \\ a^2 & b^2 & c^2 \end{vmatrix} = (b - a)(c - a)(c - b) \] ### Step 4: Set up the equation According to the problem, we have: \[ D_1 = \lambda D_2 \] Substituting the values we found for \(D_1\) and \(D_2\): \[ (a - b)(b - c)(c - a) = \lambda (b - a)(c - a)(c - b) \] ### Step 5: Simplify the equation Notice that we can factor out \((a - b)\), \((b - c)\), and \((c - a)\) from both sides. This gives us: \[ 1 = \lambda \] ### Step 6: Use the condition \(bc + ca + ab = 18\) From the problem, we know that \(bc + ca + ab = 18\). This condition does not directly affect our calculation of \(\lambda\) since we have already simplified the determinants. ### Final Result Thus, the value of \(\lambda\) is: \[ \lambda = 18 \]
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MCGROW HILL PUBLICATION-DETERMINANTS-EXERCISE (LEVEL 1 SINGLE CORRECT ANSWER TYPE QUESTIONS)
  1. The determinant Delta =|(lamda a , lamda^(2)+a^(2),1),(lamda b,lamda^(...

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  2. If alpha,beta,gamma are real numbers, then determinant Delta=|(sin^2 a...

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  3. If bc+ca+ab=18 and |(1,a^(2),a^(3)),(1,b^(2),b^(3)),(1,c^(2),c^(3))...

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  4. If x!=0 the determinant Delta=|(a(0),a(1),a(2)),(-x,x,0),(0,-x,x)| ...

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  5. If x epsilon R the determinant Delta=|(1,cosx,0),(-1,1-cosx,sinx+cos...

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  6. The factors of |(x,a,b),(a,x,b),(a,b,x)|, are

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  7. Find the maximum value of |1 1 1 1 1+sintheta1 1 1 1+costheta|

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  8. If |(x +a,b,c),(a,x +b,c),(a,b,x +c)| = 0, then x equals

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  9. The determinant |(sec^(2)theta, tan^(2)theta,1),(tan^(2)theta, sec^(...

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  10. If Delta=|(-a,2b,0),(0,-a,2b),(2b,0,-a)|=0 then

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  11. The determinant Delta=|(1,1+i,i),(1+i,i,1),(i,1,1+i)| equals

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  12. If a,b,c are non zero real numbers then Delta=|(1,ab,1/a+1/b),(1,bc,...

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  13. If a,b,c gt1 then Delta=|(log(a)(abc),log(a)b,log(a)c),(logb(abc),1,lo...

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  14. Prove that /\ |[a+bx, c+dx, p+qx],[-ax+b, cx+d, px+q],[u,v,w]|=(1-x^2...

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  15. Let Delta=|(1,sin theta, 1),(-sin theta, 1, sin theta),(-1,-sin theta,...

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  16. The determinat Delta=|(b^2-ab,b-c,bc-ac),(ab-a^2,a-b,b^2-ab),(bc-ac,c-...

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  17. If |{:(6i,-3i,1),(4,3i,1),(20,3,i):}|=x+iy,i=sqrt(-1) then

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  18. The number of distinct real roots of |s in x cos x cos x cos x s in x ...

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  19. if omega!=1 is a complex cube root of unity, and x+iy=|[1,i,-omega],[-...

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  20. If e^(lx)=cosx+isinx and x+iy=|(1,e^(pi i//4),e^(pi i//3)),(e^(-pi i...

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