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(i) If the vectors vec a+vec b+vec c = 0...

(i) If the vectors `vec a+vec b+vec c = 0` `|vec a|=3`,`|vec b|=5` and `|vec c|=7`, find the angle between a and b
(ii) If the vectors 2hat i+3hat j+4hat k and `(a-1)hat i+(b+2)hat j+8hat k` are parallel then find the values of a and b.

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MODERN PUBLICATION-TEST PAPER 8-EXERCISE
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