Find `( vec (a) xxvec (b))` and `|vec(a) xx vec (b)|`,when
(i) `vec(a) = hat(i)-hat(j)+ 2hat(k)` and `vec(b)= 2 hat(i)+3 hat(j)-4hat(k)`
(ii)`vec(a)= 2hat (i)+hat(j)+ 3hat(k)` and `vec(b)= 3hat(i)+5 hat(j) - 2 hat(k)`
(iii) `vec(a)=hat(i)- 7 hat(j)+ 7hat(k)` and `vec(b) = 3 hat(i)-2hat(j)+2 hat(k)`
(iv) `vec(a)= 4hat(i)+ hat(j)- 2hat(k)` and `vec(b) = 3 hat(i)+hat(k)`
(v) `vec(a) = 3 hat(i) + 4 hat(j)` and `vec(b) = hat(i)+hat(j)+hat(k)`

Explanation

To solve the problem, we will find the cross product of the vectors \(\vec{a}\) and \(\vec{b}\) for each part and then calculate the magnitude of the resulting vector.

### Part (i)
Given:
\[ \vec{a} = \hat{i} - \hat{j} + 2\hat{k}, \quad \vec{b} = 2\hat{i} + 3\hat{j} - 4\hat{k} \]

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