Question

If the roots of the equation ax² – 4x + a² = 0 are imaginary and the sum of the roots is equal to their product then a is :

• A. –2
• B. 4
• C. 2
• D. None of these

Answer 1

Answer: (C)

2

Answer 2

sum = product

$\frac{4}{a}$ = a ⇒ a² = 4

D < 0 ⇒ (4)² – 4a³

4(4 – a³) < 0

a = 2