Question

If P= i +2j-4k and Q= i +2j-k then the dot product of (P+Q).(P-Q) is....... *​

Answer 1

Explanation:

$(P + Q).(P - Q)$

$(2i + 4j - 5k).(-3k)$

$(2*0 + 4*0 + (-5)*(-3))$

$(0 + 0 + 15)$

$15$

Answer 2

Answer:

The answer is 15........✌️✌️✌️✌️