If - a - b -2- a - b -2-144 and - a -4- then the value of - b - isA- 1B- 2C- 3D- 4

The correct option is C 3 nbsp; nbsp; nbsp;|a×b|^2+ |a·b|^2=144 ⇒ |a|^2 |b|^2sin ^2 θ + |a|^2 |b|^2cos ^2 θ=144 ⇒ |a|^2 |b|^2=144 ⇒ 16 |b|^2 =144 ⇒ |b| ...

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Byju's Answer

Standard XII

Mathematics

Product of Trigonometric Ratios in Terms of Their Sum

If | a × b |2...

Question

$If | \to a \times \to b |^{2} + | \to a \cdot \to b |^{2} = 144$ and $| \to a | = 4$ , then the value of $| \to b |$ is

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Solution

The correct option is C $3$
$| \to a \times \to b |^{2} + | \to a \cdot \to b |^{2} = 144$
$\Rightarrow | \to a |^{2} | \to b |^{2} {sin}^{2} θ + | \to a |^{2} | \to b |^{2} {cos}^{2} θ = 144$
$\Rightarrow | \to a |^{2} | \to b |^{2} = 144$
$\Rightarrow 16 | \to b |^{2} = 144$
$\Rightarrow | \to b | = 3$

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If |→a×→b|2+|→a⋅→b|2=144 and |→a|=4, then the value of |→b| is

The correct option is C 3 |→a×→b|2+|→a⋅→b|2=144 ⇒|→a|2|→b|2sin2θ + |→a|2|→b|2cos2θ=144 ⇒|→a|2|→b|2=144 ⇒16|→b|2=144 ⇒|→b|=3

$If | \to a \times \to b |^{2} + | \to a \cdot \to b |^{2} = 144$ and $| \to a | = 4$ , then the value of $| \to b |$ is