Question

The roots of the quadratic equation x² – 1 = 0 are ______.

Options

• 0, 0

• 1, 1

• –1, –1

• +1, –1

Answer 1

The roots of the quadratic equation x² – 1 = 0 are +1, –1.

Explanation:

x² – 1 = 0

⇒ x² – 1² = 0

⇒ (x + 1)(x – 1) = 0

⇒ (x + 1) = 0 or (x – 1) = 0   ...[Using zero product rule]

⇒ x = –1 or x = 1