Question

Prove the |vector A×vector B |whole square + |A•B|whole square =(AB) whole square

Answer 1

Explanation:

I A×B I = ABsin∅

I A.B I = ABcos∅

so, I A×B I² + I A.B I² = AB²COS²∅ + AB²SIN²∅

= AB²(SIN²∅+COS²∅)

= AB²(1)

= AB² ---- hence proved

hope it might help you