Question
Download Solution PDFIn the equation \(3x^2−12x+b=0\) with equal roots, if the positions of b and 12 are interchanged, then the roots of the new equation are ____.
Answer (Detailed Solution Below)
Detailed Solution
Download Solution PDFGiven:
Original equation: 3x² − 12x + b = 0 with equal roots
Concept Used:
For equal roots, discriminant (Δ) = 0
Discriminant formula: Δ = b² − 4ac
Calculation:
For the original equation, a = 3, b = -12, c = b (unknown)
Δ = (-12)² − 4 × 3 × b = 144 − 12b = 0
⇒ 144 = 12b
⇒ b = 12
New equation:
If the positions of b and 12 are interchanged, the new equation becomes:
3x² − 12x + 12 = 0
Discriminant of the new equation:
Δ = (-12)² − 4 × 3 × 12 = 144 − 144 = 0
Since the discriminant is 0, the new equation also has equal roots.
Roots of the new equation:
Using the quadratic formula: x = (-b ± √Δ) / 2a
For 3x² − 12x + 12 = 0, a = 3, b = -12, Δ = 0
⇒ x = (-(-12) ± √0) / (2 × 3) = 12 / 6 = 2
∴ The roots of the new equation are x = 2, 2 (equal roots)
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