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If (1)/(2-sqrt(-2)) is one of the root o...

If `(1)/(2-sqrt(-2))` is one of the root of `ax^(2) + bx + c = 0`. Where a,b and c are real, then what are the value of a.b.c respectively.

A

6, -4,1

B

4,6,-1

C

3,-2,1

D

6,4,1

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To solve the problem, we need to find the values of \( a \), \( b \), and \( c \) in the quadratic equation \( ax^2 + bx + c = 0 \) given that one of the roots is \( \frac{1}{2 - \sqrt{-2}} \). ### Step 1: Simplify the root The root given is \( \frac{1}{2 - \sqrt{-2}} \). We can rewrite \( \sqrt{-2} \) as \( i\sqrt{2} \) (where \( i \) is the imaginary unit). So, we have: \[ \frac{1}{2 - i\sqrt{2}} \] ### Step 2: Multiply by the conjugate To simplify this expression, we multiply the numerator and the denominator by the conjugate of the denominator: \[ \frac{1 \cdot (2 + i\sqrt{2})}{(2 - i\sqrt{2})(2 + i\sqrt{2})} \] ### Step 3: Calculate the denominator The denominator simplifies as follows: \[ (2 - i\sqrt{2})(2 + i\sqrt{2}) = 2^2 - (i\sqrt{2})^2 = 4 - (-2) = 4 + 2 = 6 \] ### Step 4: Calculate the numerator The numerator becomes: \[ 2 + i\sqrt{2} \] ### Step 5: Combine results Thus, we have: \[ \frac{2 + i\sqrt{2}}{6} = \frac{1}{3} + \frac{i\sqrt{2}}{6} \] ### Step 6: Identify the roots Since \( \frac{1}{2 - i\sqrt{2}} \) is a root, the other root (by the property of complex conjugates) is: \[ \frac{1}{2 + i\sqrt{2}} = \frac{2 - i\sqrt{2}}{6} = \frac{1}{3} - \frac{i\sqrt{2}}{6} \] ### Step 7: Sum and product of roots Let the roots be \( r_1 = \frac{1}{3} + \frac{i\sqrt{2}}{6} \) and \( r_2 = \frac{1}{3} - \frac{i\sqrt{2}}{6} \). The sum of the roots \( r_1 + r_2 \) is: \[ \left(\frac{1}{3} + \frac{i\sqrt{2}}{6}\right) + \left(\frac{1}{3} - \frac{i\sqrt{2}}{6}\right) = \frac{2}{3} \] The product of the roots \( r_1 \cdot r_2 \) is: \[ \left(\frac{1}{3} + \frac{i\sqrt{2}}{6}\right)\left(\frac{1}{3} - \frac{i\sqrt{2}}{6}\right) = \left(\frac{1}{3}\right)^2 + \left(\frac{\sqrt{2}}{6}\right)^2 = \frac{1}{9} + \frac{2}{36} = \frac{1}{9} + \frac{1}{18} = \frac{2}{18} + \frac{1}{18} = \frac{3}{18} = \frac{1}{6} \] ### Step 8: Form the quadratic equation Using the sum and product of the roots, we can form the quadratic equation: \[ x^2 - \left(\frac{2}{3}\right)x + \frac{1}{6} = 0 \] ### Step 9: Clear the fractions To eliminate the fractions, multiply through by 6: \[ 6x^2 - 4x + 1 = 0 \] ### Step 10: Identify \( a \), \( b \), and \( c \) From the equation \( 6x^2 - 4x + 1 = 0 \), we identify: - \( a = 6 \) - \( b = -4 \) - \( c = 1 \) ### Final Answer Thus, the values of \( a \), \( b \), and \( c \) are: \[ a = 6, \quad b = -4, \quad c = 1 \]
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