Question

10. If A = 2i – 2j and B = 2k, then A.B = ___​

Answer 1

Answer:

ik=jk

Explanation:

A=2i-2j B=2k

(2i-2j)(2k)

2i2k-2j2k=0

2(ik)-2(jk)=0

2(ik)=2(jk)

ik=jk

Answer 2

$\vec{A} \cdot \vec{B} = (2 \hat{i} - 2 \hat{j} )\cdot(2 \hat{k} )$

$\vec{A} \cdot \vec{B} = 4 \: \hat{i} \cdot \hat{k} - 4 \: \hat{j} \cdot \hat{k } = \boxed{0}$