Ir a,b,č are unit vectors such that a+bätbč 0, find

1.	Ir a,b,č are unit vectors such that a+bätbč 0, find
Answer» a+b+c = 0 take dot product with (a+b+c) both sides... (a+b+c). (a+b+c) = 0 a.a + a.b+a.c + b.a + b.b+ b.c+c.a+c.b+c.c = 0 2(a.b+b.c+c.a) +\|a^2\|+ \| b2\|+ \| c2\|= 0 ...........(a.b =b.a , b.a=a.b , c.a=a.c , ..) 2(a.b+b.c+c.a) = -3 .....(since mode a = mode b = mode c = 1 ) a.b+b.c+c.a = -3/2

Answer»

a+b+c = 0

take dot product with (a+b+c) both sides...

(a+b+c). (a+b+c) = 0

a.a + a.b+a.c + b.a + b.b+ b.c+c.a+c.b+c.c = 0

2(a.b+b.c+c.a) +|a^2|+ | b2|+ | c2|= 0 ...........(a.b =b.a , b.a=a.b , c.a=a.c , ..)

2(a.b+b.c+c.a) = -3 .....(since mode a = mode b = mode c = 1 )

a.b+b.c+c.a = -3/2

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