Question

What will be the nature of the roots of the quadratic equation 2x^2 + 10x + 9?

(a) Imaginary

(b) Real

(c) Irrational

(d) Equal

I had been asked this question in a job interview.

Question is taken from Quadratic Equation in chapter Quadratic Equation of Mathematics – Class 10

Answer 1

Right choice is (b) Real

Explanation: To check the nature of the roots, the discriminant must be either equal to zero, less than zero or greater than zero.

Discriminant = b^2 – 4ac = 10^2 – 4 × 2 × 9 = 100 – 72 = 28

Since discriminant is greater than zero, the roots of the equation are real and distinct.