If |p+q|=|p-q|, then p*q must be equal to:	Pick one.
A) 0 B) -2 C) -1 D) 1 E) 1
Solution 1: Distance perspective   |p-q| = |p+q| ==&gt; The distance of p and q is equal to the distance of p and -q.   &lt;=======(-q)=======0=======(q)======&gt;   Only 0 is the value that has a distance equal to q and -q.   Solution 2:   |p-q| = |p+q| (square both)   p^2 -2pq + q^2 = p^2 + 2pq + q^2   4pq = 0   pq = 0   0nswer: 0
<result>A</result>
If |p+q|=|p-q|, then p*q must be equal to: