Question

If a, b, c be the sides of DABC and equations ax² + bx + c = 0 and 5x² +12x + 13 = 0 have a common root, then ŠC is-

• A. 60⁰
• B. 90⁰
• C. 120⁰
• D. 45⁰

Answer 1

Answer: (B)

90⁰

Answer 2

From equation (ii)

D = (12)² –4.5.13 = –116 < 0

Hence root of equation (ii) are non real

Hence both equations have same roots

So a : b : c = 5 : 12 : 13

Let a = 5k, b = 12k, c = 13 k

Here c² = a² + b²

Ž ŠC = 90⁰