Unit Vectors at 120120^\circ

6/10SubstitutionalgebraAM-GMvectors

Problem

Unit vectors e1,e2\vec e_1, \vec e_2 make an angle of 120120^\circ, and reals x,yx, y satisfy

xe1+ye2=3.\left|x\vec e_1 + y\vec e_2\right| = \sqrt3.

Find the range of xe1ye2\left|x\vec e_1 - y\vec e_2\right|.

Answer

Solution

Difficulty6/10
TopicsSubstitution, algebra, AM-GM, vectors

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