Correct Answer - Option 3 : 16
Concept:
The roots of a quadratic equation ax2 + bx + c = 0 is give by:
\(\rm x = {-b \pm \sqrt{b^2-4ac} \over 2a}\)
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 + 8x + 1 = 0
a = a, b = 8 and c = 1
Given: The roots are real and equal
So, D = 0
82 - 4 × a × 1 = 0
64 = 4a
a = 16
