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If the equation x^(2)- bx+ 1 = 0 does no...

If the equation `x^(2)- bx+ 1 = 0` does not possess real roots, then which one of the following is correct?

A

` -3 lt b lt 3`

B

` -2 lt b lt 2 `

C

` b gt 2`

D

` b lt -2`

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The correct Answer is:
To determine the conditions under which the quadratic equation \( x^2 - bx + 1 = 0 \) does not possess real roots, we need to analyze the discriminant of the equation. ### Step-by-step Solution: 1. **Identify the coefficients**: The given quadratic equation is in the form \( ax^2 + bx + c = 0 \), where: - \( a = 1 \) - \( b = -b \) (the coefficient of \( x \)) - \( c = 1 \) 2. **Write the discriminant**: The discriminant \( D \) of a quadratic equation \( ax^2 + bx + c = 0 \) is given by: \[ D = b^2 - 4ac \] Substituting the values of \( a \), \( b \), and \( c \): \[ D = (-b)^2 - 4 \cdot 1 \cdot 1 \] This simplifies to: \[ D = b^2 - 4 \] 3. **Condition for no real roots**: For the quadratic equation to not possess real roots, the discriminant must be less than zero: \[ D < 0 \] Therefore, we set up the inequality: \[ b^2 - 4 < 0 \] 4. **Solve the inequality**: Rearranging the inequality gives: \[ b^2 < 4 \] Taking the square root of both sides, we find: \[ -2 < b < 2 \] 5. **Conclusion**: The values of \( b \) that satisfy this inequality indicate that \( b \) must be between -2 and 2 (exclusive). Thus, the correct answer is: \[ -2 < b < 2 \]

To determine the conditions under which the quadratic equation \( x^2 - bx + 1 = 0 \) does not possess real roots, we need to analyze the discriminant of the equation. ### Step-by-step Solution: 1. **Identify the coefficients**: The given quadratic equation is in the form \( ax^2 + bx + c = 0 \), where: - \( a = 1 \) - \( b = -b \) (the coefficient of \( x \)) ...
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