Question

if p.q=0 and p×r=0 then angle between q and r is
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Answer 1

Answer:

Assuming all three vectors p, q and r have some non-zero value, the angle between q and r vector is 90°. As p.q=0, p is perpendicular to q and p×r=0, r is parallel to p. It implies that r is also perpendicular to q.

Answer 2

Answer:

The solution is 90 degrees.

Explanation:

It is given in the question that p.q= 0

so, it means  $|p||q|cos\phi=0$, where $\phi$ is the angle between p and q.

Assuming P and Q to be non-zero vectors, so we can say $Cos\phi=0$, or else we can say $\phi= 90\textdegree$ .

So, it means the angle between p and q is  90 degrees.

Now the second given thing is p X r =0, from this we can say  $|p||r|sin\theta=0$  where $\theta$ is the angle between p and r.

So, proceeding to calculation and assuming the previous logic that p and r are non-zero vectors, we can say that $sin\theta=0$ , or we can say that $\theta = 0\textdegree$.

So, it means p and r are parallel.

Hence angle between q and r is the same as that of p and q.

Therefore the angle between q and r is 90 degrees.