- Home
- Standard 11
- Physics
3-1.Vectors
medium
$ (\overrightarrow A + \overrightarrow B )\, \times (\overrightarrow A - \overrightarrow B ) $ = ______
A
$0$
B
$ {A^2} - {B^2} $
C
$ \overrightarrow B \times \overrightarrow A $
D
$ 2(\overrightarrow B \times \overrightarrow A ) $
Solution
(d)$(\vec A + \vec B) \times (\vec A – \vec B)$
$ = \vec A \times \vec A – \vec A \times \vec B + \vec B \times \vec A – \vec B \times \vec B$
$ = 0 – \vec A \times \vec B + \vec B \times \vec A – 0$
$ = \vec B \times \vec A + \vec B \times \vec A = 2(\vec B \times \vec A)$
Standard 11
Physics
