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If a,b,c,d gt 0 , x in R and (a^(2)+b^(2...

If `a,b,c,d gt 0` , `x in R` and `(a^(2)+b^(2)+c^(2))x^(2)-2(ab+bc+cd)x+b^(2)+c^(2)+d^(2) le 0`, then `|{:(33,14,loga),(65,27,logb),(97,40,logc):}|=`

A

`1`

B

`-1`

C

`0`

D

none of these

Text Solution

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The correct Answer is:
To solve the given problem, we need to analyze the inequality and the determinant provided. Let's break it down step by step. ### Step 1: Analyze the Inequality We start with the inequality: \[ (a^2 + b^2 + c^2)x^2 - 2(ab + bc + cd)x + (b^2 + c^2 + d^2) \leq 0 \] This is a quadratic inequality in terms of \(x\). For this quadratic to be less than or equal to zero for all \(x\), the discriminant must be less than or equal to zero. ### Step 2: Calculate the Discriminant The discriminant \(D\) of a quadratic equation \(Ax^2 + Bx + C\) is given by: \[ D = B^2 - 4AC \] Here, \(A = a^2 + b^2 + c^2\), \(B = -2(ab + bc + cd)\), and \(C = b^2 + c^2 + d^2\). Calculating the discriminant: \[ D = (-2(ab + bc + cd))^2 - 4(a^2 + b^2 + c^2)(b^2 + c^2 + d^2) \] \[ D = 4(ab + bc + cd)^2 - 4(a^2 + b^2 + c^2)(b^2 + c^2 + d^2) \] ### Step 3: Set the Discriminant Less Than or Equal to Zero For the quadratic to be non-positive: \[ 4(ab + bc + cd)^2 - 4(a^2 + b^2 + c^2)(b^2 + c^2 + d^2) \leq 0 \] Dividing by 4: \[ (ab + bc + cd)^2 \leq (a^2 + b^2 + c^2)(b^2 + c^2 + d^2) \] ### Step 4: Analyze the Equality Condition The equality holds when: \[ (ab + bc + cd)^2 = (a^2 + b^2 + c^2)(b^2 + c^2 + d^2) \] This leads to the conditions on \(a\), \(b\), \(c\), and \(d\). ### Step 5: Determine the Values of \(b\) From the equality condition, we can derive relationships among \(a\), \(b\), \(c\), and \(d\). Specifically, we can express: \[ b^2 = ac \quad \text{and} \quad c^2 = bd \] ### Step 6: Take Logarithms Taking logarithms of the relationships: \[ 2 \log b = \log a + \log c \] This implies: \[ \log a + \log c - 2 \log b = 0 \] ### Step 7: Set Up the Determinant Now we need to evaluate the determinant: \[ \begin{vmatrix} 33 & 14 & \log a \\ 65 & 27 & \log b \\ 97 & 40 & \log c \end{vmatrix} \] ### Step 8: Perform Row Operations We can perform row operations to simplify the determinant. For instance, we can replace the first row with \(R_1 + R_3\): \[ R_1 \rightarrow R_1 + R_3 \] This gives us: \[ \begin{vmatrix} 130 & 54 & \log a + \log c \\ 65 & 27 & \log b \\ 97 & 40 & \log c \end{vmatrix} \] ### Step 9: Evaluate the Determinant Now we can calculate the determinant. If we find that the determinant equals zero, we conclude: \[ | \{(33, 14, \log a), (65, 27, \log b), (97, 40, \log c)\} | = 0 \] ### Conclusion Thus, the final answer is: \[ | \{(33, 14, \log a), (65, 27, \log b), (97, 40, \log c)\} | = 0 \]

To solve the given problem, we need to analyze the inequality and the determinant provided. Let's break it down step by step. ### Step 1: Analyze the Inequality We start with the inequality: \[ (a^2 + b^2 + c^2)x^2 - 2(ab + bc + cd)x + (b^2 + c^2 + d^2) \leq 0 \] This is a quadratic inequality in terms of \(x\). For this quadratic to be less than or equal to zero for all \(x\), the discriminant must be less than or equal to zero. ...
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