If a-2i-3j-b-2j-3k- then a-b- - a-b- -

The correct option is A 0 a =2i 3j,b=2j+3k (a+b)·(a b)=a·a b·b=13 13=0 ∴ (a+b)·(a b)=0 Hence, option A. ...

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Byju's Answer

Standard XII

Mathematics

Applications of Dot Product

If a⃗=2i-3j...

Question

If $\to a = 2 i - 3 j, \to b = 2 j + 3 k,$ then $(\to a + \to b) . (\to a - \to b) =$

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Solution

The correct option is A 0
$¯ ¯ ¯ a = 2 ¯ i - 3 ¯ j, ¯ ¯ b = 2 ¯ j + 3 ¯ ¯ ¯ k$
$(¯ ¯ ¯ a + ¯ ¯ b) \cdot (¯ ¯ ¯ a - ¯ ¯ b) = ¯ ¯ ¯ a \cdot ¯ ¯ ¯ a - ¯ ¯ b \cdot ¯ ¯ b = 13 - 13 = 0$
$∴ (¯ ¯ ¯ a + ¯ ¯ b) \cdot (¯ ¯ ¯ a - ¯ ¯ b) = 0$
Hence, option A.

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Similar questions

Let $\to a = i + 2 j + 3 k$ if $\to b$ is a vector such that $\to a, \to b = | \to b |$ and $| \to a - \to b | = \sqrt{7}$ , then $| \to b | =$ ____________

Q. Find

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is?

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If →a=2i−3j,→b=2j+3k, then (→a+→b).(→a−→b)=

The correct option is A 0¯¯¯a=2¯i−3¯j,¯¯b=2¯j+3¯¯¯k(¯¯¯a+¯¯b)⋅(¯¯¯a−¯¯b)=¯¯¯a⋅¯¯¯a−¯¯b⋅¯¯b=13−13=0∴(¯¯¯a+¯¯b)⋅(¯¯¯a−¯¯b)=0Hence, option A.

If $\to a = 2 i - 3 j, \to b = 2 j + 3 k,$ then $(\to a + \to b) . (\to a - \to b) =$

The correct option is A 0
$¯ ¯ ¯ a = 2 ¯ i - 3 ¯ j, ¯ ¯ b = 2 ¯ j + 3 ¯ ¯ ¯ k$
$(¯ ¯ ¯ a + ¯ ¯ b) \cdot (¯ ¯ ¯ a - ¯ ¯ b) = ¯ ¯ ¯ a \cdot ¯ ¯ ¯ a - ¯ ¯ b \cdot ¯ ¯ b = 13 - 13 = 0$
$∴ (¯ ¯ ¯ a + ¯ ¯ b) \cdot (¯ ¯ ¯ a - ¯ ¯ b) = 0$
Hence, option A.