Question

The roots of the equation ax2 + bx + c = 0 will be reciprocal if:

(a) a = b, (b) a = bc, (c) c = a, (d) c = b, (e) c = ab.​

Answer 1

Solution:

Let k be one of the root of the given equation.

According to the problem,

1/k will be the other root of the given equation.

We know that, product of the roots of the equation = c/a.

Therefore, k × 1/k = c/a.

or, 1 = c/a.

or, a = c [multiplying a on both sides].

The roots of the equation ax2 + bx + c = 0 will be reciprocal if a = c.

Therefore, a = c or c = a.

Answer: (c)