Vectors (JEE 99)

Let a and b be 2 non collinear unit vectors . u=a-(a.b)b and v = a x b,then |v| = ? (in terms of u , a,b)

1 Answers

sorry, i dont know how to keep bars overhead

let angle between a and b be cos Î¸ . u =a-b cosÎ¸

|v|=sinÎ¸

u^2= 1+cos²Î¸-2cos²Î¸
=1-cos²Î¸=sin²Î¸ =|v|²

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