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If the position vector of a point P with respect to origin O is î + 3ĵ - 2k̂ and that of a point Q is 3î + ĵ - 2k̂, then what is the position vector of the bisector of the angle POQ? 1. î - ĵ - k̂ 2. î + ĵ - k̂ 3. î + ĵ + k̂ 4. None of the above |
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Answer» Correct Answer - Option 4 : None of the above Concept: A triangle ABC is said to be an isosceles triangle if triangle ABC must have two sides of equal length. Calculations: Given, the position vector of a point P with respect to origin O is î + 3ĵ - 2k̂ and that of a point Q is 3î + ĵ - 2k̂. ⇒\(\rm \bar {OP} \) = î + 3ĵ - 2k̂ and \(\rm \bar {OQ}\) = 3î + ĵ - 2k̂. ⇒ |OP| = \(\rm \sqrt {1+9 + 4} = \sqrt {15}\) ⇒ |OQ| = \(\rm \sqrt {9 + 1+ 4} = \sqrt {15}\) Here, |OP| = |OQ| \(\rm \triangle POQ\) is isoscale. The position vector of the bisector of the angle POQ = \(\rm \dfrac 1 2 (OP + OQ)\) ⇒The position vector of the bisector of the angle POQ = \(\rm \dfrac 1 2 [(î + 3ĵ - 2k̂) + (3î + ĵ - 2k̂)]\) ⇒The position vector of the bisector of the angle POQ = \(\rm \dfrac 1 2 (4î + 4ĵ - 4k̂) \) ⇒The position vector of the bisector of the angle POQ = \(\rm 2î + 2ĵ - 2k̂\) |
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