NTA Abhyas JEE Main2020MathematicsQuadratic EquationPractice
If the equation a x 2 + 2 b x - 3 c = 0 has no real roots and 3 c 4 < a + b , then
Options
- Ac < 0
- Bc > 0
- Cc = 0
- Da + 2 b - 3 c < 0
Correct answer
A. c < 0
Step-by-step solution
a x 2 + 2 b x - 3 c = 0 has no real roots f 2 = 4 a + 4 b - 3 c = 4 a + b - 3 c 4 > 0 (given) So, f x > 0   ∀ x ⇒ f 0 > 0 ⇒ - 3 c > 0 ⇒ c < 0