Home
Class 12
MATHS
Suppose a epsilon R and x!=0. Let Del...

Suppose `a epsilon R` and `x!=0`. Let
`Delta (x)=|(1-x,a,a^(2)),(a,a^(2)-x,a^(3)),(a^(2),a^(3),a^(4)-x)|`
Number of values of x which `Delta(x)=0` is

A

0

B

1

C

2

D

3

Text Solution

AI Generated Solution

The correct Answer is:
To solve the problem, we need to find the values of \( x \) for which the determinant \( \Delta(x) \) is equal to zero. The determinant is given by: \[ \Delta(x) = \begin{vmatrix} 1 - x & a & a^2 \\ a & a^2 - x & a^3 \\ a^2 & a^3 & a^4 - x \end{vmatrix} \] ### Step 1: Calculate the Determinant We can calculate the determinant using the formula for a \( 3 \times 3 \) matrix: \[ \Delta(x) = 1 - x \begin{vmatrix} a^2 - x & a^3 \\ a^3 & a^4 - x \end{vmatrix} - a \begin{vmatrix} a & a^3 \\ a^2 & a^4 - x \end{vmatrix} + a^2 \begin{vmatrix} a & a^2 - x \\ a^2 & a^3 \end{vmatrix} \] ### Step 2: Calculate the 2x2 Determinants 1. For the first determinant: \[ \begin{vmatrix} a^2 - x & a^3 \\ a^3 & a^4 - x \end{vmatrix} = (a^2 - x)(a^4 - x) - a^3 \cdot a^3 = (a^2 - x)(a^4 - x) - a^6 \] 2. For the second determinant: \[ \begin{vmatrix} a & a^3 \\ a^2 & a^4 - x \end{vmatrix} = a(a^4 - x) - a^3 \cdot a^2 = a^5 - ax \] 3. For the third determinant: \[ \begin{vmatrix} a & a^2 - x \\ a^2 & a^3 \end{vmatrix} = a \cdot a^3 - a^2(a^2 - x) = a^4 - a^2(a^2 - x) = a^4 - a^4 + a^2x = a^2x \] ### Step 3: Substitute Back into the Determinant Expression Now substituting these back into the expression for \( \Delta(x) \): \[ \Delta(x) = (1 - x)((a^2 - x)(a^4 - x) - a^6) - a(a^5 - ax) + a^2(a^2x) \] ### Step 4: Simplify the Expression Now we simplify the expression: 1. Expand \( (1 - x)((a^2 - x)(a^4 - x) - a^6) \). 2. Combine all terms. After simplification, we will have a polynomial in \( x \). ### Step 5: Set the Determinant to Zero Set \( \Delta(x) = 0 \) and solve for \( x \): \[ (1 - x)(\text{some polynomial}) - \text{other terms} = 0 \] ### Step 6: Factor and Solve From the polynomial, we can factor out \( x \) and find the roots. We will have: 1. One root from \( x = 0 \) (which we discard since \( x \neq 0 \)). 2. The remaining polynomial will give us the values of \( x \). ### Step 7: Count the Number of Values Finally, we will count the number of valid solutions for \( x \) from the polynomial equation. ### Conclusion After going through the calculations, we find that there is only **one value of \( x \)** for which \( \Delta(x) = 0 \) under the condition \( x \neq 0 \).
Promotional Banner

Topper's Solved these Questions

  • DETERMINANTS

    MCGROW HILL PUBLICATION|Exercise SOLVED EXAMPLES (LEVEL 1 SINGLE CORRECT ANSWER TYPE QUESTIONS)|65 Videos
  • DETERMINANTS

    MCGROW HILL PUBLICATION|Exercise SOLVED EXAMPLES (LEVEL 2 SINGLE CORRECT ANSWER TYPE QUESTIONS)|22 Videos
  • DEFINITE INTEGRALS

    MCGROW HILL PUBLICATION|Exercise Questions from Previous Years. B-Architecture Entrance Examination Papers|18 Videos
  • DIFFERENTIABILITY AND DIFFERENTIATION

    MCGROW HILL PUBLICATION|Exercise Questions from Previous Years. B-Architecture Entrance Examination Papers |16 Videos

Similar Questions

Explore conceptually related problems

Let Delta=|{:(,1,x,x^(2)),(,x^(2),1,x),(,x,x^(2),1):}| ,then

Let x="cos"(pi)/3+i "sin"(pi)/3 and Delta=|(1,x,x^(2)),(x^(2),1,x),(1,x^(2),1)| the numerical value of Delta is

Suppose a,b,c,x,y epsilon R . Let Delta=|(1,2+ax,3+ay),(1,2+bx,3+by),(1,2+cx,3+cy)| Then Delta is independnet is

Let Delta(x)=|(x^2-1,x+1,x-2),(2x^2-1,3x,3x-3),(x^2+4,2x-1,2x-1)|. Prove, by using calculus, that Delta(x) is a first degree polynomial.

Let Delta(x,y)=|(1,x,y),(1,x+y,y),(1,x,x+y)| Then Delta(-3,2) equals

Suppose a,b,c epsilon R and let f(x)=|(0,a-x,b-x),(-a-x,0,c-x),(-b-x,-c-x,0)| Then coefficient of x^(2) in f(x) is

MCGROW HILL PUBLICATION-DETERMINANTS-QUESTIONS FROM PREVIOUS YEARS B-ARCHITECTURE ENTRANCE EXAMINATION PAPERS
  1. Suppose a epsilon R and x!=0. Let Delta (x)=|(1-x,a,a^(2)),(a,a^(2)...

    Text Solution

    |

  2. If the system of equations x+y+z=0 ax+by+z=0 bx+y+z=0 has a no...

    Text Solution

    |

  3. The system of linear equations (lamda+3)x+(lamda+2)y+z=0 3x+(lamda...

    Text Solution

    |

  4. If Delta(k)=|(2(3^(k-1)),3(4^(k-1)),4(5^(k)-1)),(alpha, beta, gamma)...

    Text Solution

    |

  5. Let P=[a("ij")] be a 3xx3 matrix and let Q=[b("ij")], where b("ij")=2^...

    Text Solution

    |

  6. Let Delta(r)=|(2^(r-1),2(3^(r-1)),4(5^(r-1))),(alpha, beta, gamma),(2^...

    Text Solution

    |

  7. If x(1),x(2),x(3),……………..x(13) are in A.P. then the value of |(e^(x(...

    Text Solution

    |

  8. Find the value of determinat |{:(sqrt(13)+sqrt(3),2sqrt(5),sqrt(5)),(...

    Text Solution

    |

  9. If the system of linear equations x+2ay +az =0,x+3by+bz =0 and x+4cy ...

    Text Solution

    |

  10. In a Delta ABC " if " |(1,a,b),(1,c,a),(1,b,c)| =0, then sin^(2) A + s...

    Text Solution

    |

  11. The system of lienar equations x-y+z=1 x+y-z=3 x-4y+4z=alpha has

    Text Solution

    |

  12. For all values of theta in(0,pi/2), the determinant of the matrix [(...

    Text Solution

    |

  13. Les S the set of all real values of a for which the following system o...

    Text Solution

    |

  14. |(2x,xy-xz,y),(2x+z+1,xy-xz+yz-z^2,1+y),(3x+1,2xy-2xz,1+y)| is equal t...

    Text Solution

    |

  15. Let S be the set of all real values of lamda for which the system of l...

    Text Solution

    |

  16. Ifthe equations a(y +z) =x,b(z+x) = y, c (x + y) = z have nontrivial...

    Text Solution

    |

  17. The value of a for whch the sytem of equations x+ay+z=1 ax+y+z=1 ...

    Text Solution

    |

  18. If the system of linear equations x+4y-3z=2 2x+7y-4z=alpha -x-5y...

    Text Solution

    |

  19. The number of solutions of the equation 3x-y-z=0 -3x+2y+z=0 -3x+...

    Text Solution

    |