Question

If P+Q=P-Q (where P and Q are vectors) then the magnitude of vector Q is ​

Answer 1

Answer:

|P+Q|=|P-Q|

or, |P+Q|.|P+Q|=|P-A|.P-Q|[by doing dot product with ownself on both sides of the equation]

or, P^2+Q^2+2* P.Q=P^2+Q^2-2* P.Q

or, 4* P.Q= 4PQcos theta=0[let theta be the angle between P and Q]

Since, neither 4, nor P, nor Q is equal to 0, so, cos theta=0=cos 90

So, theta=90 degree.

So, P and Q are orthogonal to each other (Answer)

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Hope it helps you!!

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