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Statement -1 If x,y,z be real variables ...

Statement -1 If `x,y,z` be real variables satisfying `x+y+z=6` and `xy+yz+z=8`, the range of variables x,y and z are identical.
Statement -2 `x+y+z=6` and `xy+yz+zx=8` remains same if `x,y,z` interchange their positions.

A

Statement -1 is true, Statement -2 is true, Statement -2 is a correct explanation for Statement-1

B

Statement -1 is true, Statement -2 is true, Statement -2 is not a correct explanation for Statement -1

C

Statement -1 is true, Statement -2 is false

D

Statement -1 is false, Statement -2 is true

Text Solution

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The correct Answer is:
To solve the problem, we need to analyze the given statements and derive the necessary equations. Let's break it down step by step. ### Step 1: Understand the given equations We have two equations: 1. \( x + y + z = 6 \) (Equation 1) 2. \( xy + yz + zx = 8 \) (Equation 2) ### Step 2: Express one variable in terms of the others From Equation 1, we can express \( z \) in terms of \( x \) and \( y \): \[ z = 6 - x - y \] ### Step 3: Substitute \( z \) into Equation 2 Now, substitute \( z \) into Equation 2: \[ xy + y(6 - x - y) + x(6 - x - y) = 8 \] Expanding this gives: \[ xy + 6y - xy - y^2 + 6x - x^2 - xy = 8 \] Combine like terms: \[ 6x + 6y - x^2 - y^2 - xy = 8 \] ### Step 4: Rearranging the equation Rearranging the equation leads to: \[ x^2 + y^2 + xy - 6x - 6y + 8 = 0 \] ### Step 5: Treat this as a quadratic in \( y \) We can treat this as a quadratic equation in \( y \): \[ y^2 + (x - 6)y + (x^2 - 6x + 8) = 0 \] For \( y \) to have real solutions, the discriminant must be non-negative: \[ D = (x - 6)^2 - 4(x^2 - 6x + 8) \geq 0 \] ### Step 6: Calculate the discriminant Calculating the discriminant: \[ D = (x - 6)^2 - 4(x^2 - 6x + 8) \] Expanding this: \[ D = x^2 - 12x + 36 - 4x^2 + 24x - 32 \] Combine like terms: \[ D = -3x^2 + 12x + 4 \geq 0 \] ### Step 7: Solve the inequality To find the range of \( x \), we can solve the quadratic inequality: \[ 3x^2 - 12x - 4 \leq 0 \] Finding the roots using the quadratic formula: \[ x = \frac{-b \pm \sqrt{b^2 - 4ac}}{2a} = \frac{12 \pm \sqrt{144 + 48}}{6} = \frac{12 \pm \sqrt{192}}{6} = \frac{12 \pm 8\sqrt{3}}{6} = 2 \pm \frac{4\sqrt{3}}{3} \] ### Step 8: Determine the range for \( x, y, z \) Thus, the range for \( x \) is: \[ 2 - \frac{4\sqrt{3}}{3} \leq x \leq 2 + \frac{4\sqrt{3}}{3} \] Since \( y \) and \( z \) are symmetric in the equations, they will have the same range. ### Conclusion The ranges of \( x, y, \) and \( z \) are identical, confirming that **Statement 1 is true**. **Statement 2** is also true since the equations remain the same when \( x, y, z \) are interchanged.

To solve the problem, we need to analyze the given statements and derive the necessary equations. Let's break it down step by step. ### Step 1: Understand the given equations We have two equations: 1. \( x + y + z = 6 \) (Equation 1) 2. \( xy + yz + zx = 8 \) (Equation 2) ### Step 2: Express one variable in terms of the others ...
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