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If \(\sin (\alpha)\) and \(\cos (\alpha)\) are the roots of the equation \(a x^{2}+b x+c=0\), then \(b^{2}\) is

Question and options

If sin⁡(α)\sin (\alpha) and cos⁡(α)\cos (\alpha) are the roots of the equation ax2+bx+c=0a x^{2}+b x+c=0, then b2b^{2} is
  1. c2+2acc^{2}+2 a c
  2. a2+aca^{2}+a c
  3. a2+2aca^{2}+2 a c
  4. c2+acc^{2}+a c

Answer and explanation

Correct answer: C - \(a^{2}+2 a c\)
sin + cos = -b/a and sin x cos = c/a. Squaring: 1 + 2c/a = b^2/a^2, so b^2 = a^2 + 2ac.

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