Correct Answer - Option 3 : 3
Concept:
The roots of a quadratic equation ax2 + bx + c = 0 is give by:
\(\rm x = {-b ± \sqrt{b^2-4ac} \over 2a}\)
The discriminant of the equation is D = b2 - 4ac
- D > 0, roots are unequal and real
- D < 0, roots are imaginary
- D = 0, roots are real and equal
Calculation:
Given quadratic equation:
ax2 + 12x + 12 = 0
a = a, b = 12 and c = 12
∵ Roots are real and equal, D = 0
b2 - 4ac = 0
122 - 4 × a × 12 = 0
144 = 48a
a = 3
