If a- and b- are two vectors then the value of a-b- - a-b- is-

The correct option is A 2 ( b⃗×a⃗ ) (a⃗ +b⃗ )× (a⃗ b⃗ ) =a⃗× (a⃗ b⃗ )+b⃗× (a⃗ b⃗ ) #160; #160; #160; #160; #160; #160; #160; ...

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Byju's Answer

Standard XII

Mathematics

Integration of Trigonometric Functions

If a⃗ and ...

Question

If $\to a$ and $\to b$ are two vectors then the value of $(\to a + \to b) \times (\to a - \to b)$ is:

2 (\to b \times \to a)

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- 2 (\to b \times \to a)

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\to b \times \to a

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\to a \times \to b

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Solution

The correct option is A $2 (\to b \times \to a)$
$(\to a + \to b) \times (\to a - \to b) = \to a \times (\to a - \to b) + \to b \times (\to a - \to b)$
$= \to a \times \to a - \to a \times \to b + \to b \times \to a - \to b \times \to b$
Now, cross product of a vector with itself is zero ( $θ$ = 0, thus $s i n θ$ = 0)
Also, $\to a \times \to b = - (\to b \times \to a)$
Hence, given equation becomes $0 + \to b \times \to a + \to b \times \to a + 0$
which gives $2 (\to b \times \to a)$

Suggest Corrections

Similar questions

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If →a and →b are two vectors then the value of (→a+→b)×(→a−→b) is:

If $\to a$ and $\to b$ are two vectors then the value of $(\to a + \to b) \times (\to a - \to b)$ is: