Consider two points P and Q with position vectors ` vec( O P)=3 vec( a)-2 vec( b)` and ` vec(O Q)= vec( a)+vec( b)`Find the position vector of a point R which divides the line joining P and Q in the ratio 2:1,
(i) internally, and (ii) externally.

Explanation

Position vector of `P= 3 veca −2 vecb`




Position vector of` Q= veca+ vecb`



Point R divides segment PQ in ratio 2:1 externally.
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