The condition under which vectors (a+ b) and (a - b) should be at right angles to each other is

Question

The condition under which vectors (a+ b) and (a - b) should be at right angles to each other is (A) a ≠ b (B) a . b = 0 (C) | a | = | b | (D) a . b = 1

Tardigrade Admin · Accepted Answer

The dot product of two vectors should be equal to zero. is (a + b)⋅(a - b) = 0 ⇒ a2 - b2 = 0 ⇒ | a | = | b |

Q. The condition under which vectors (a+ b) and (a - b) should be at right angles to each other is

$a \neq = b$

a . b = 0

| a | = | b |

a . b = 1

The dot product of two vectors should be equal to zero.
is $(a + b) \cdot (a - b) = 0$
$\Rightarrow a^{2} - b^{2} = 0$
$\Rightarrow ∣ a ∣ = ∣ b ∣$