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प्रश्न
Find the position vector of a point which divides the join of points with position vectors `veca-2vecb" and "2veca+vecb`externally in the ratio 2 : 1
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उत्तर
Let A and B be the points with position vectors `veca-2vecb" and "2veca+vecb`respectively.
Also, let R divide AB externally in the ratio 2 : 1.
`:."Position vector of R"=(2xx(2veca+vecb)-1xx(veca-2vecb))/(2-1)=3veca+4vecb`
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