Q.

Let A(2, 3, 5) and C(–3, 4, –2) be opposite vertices of a parallelogram ABCD. If the diagonal BD=i^+2j^+3k^, then the area of the parallelogram is equal to          [2024]

1 12410  
2 12474  
3 12586  
4 12306  

Ans.

(2)

Area of parallelogram ABCD

=12|AC×BD|

=12|(5i^+j^7j^)×(i^+2j^+3k^)|

=12||i^j^k^517123||

=12|(3+14)i^(-15+7)j^+(101)k^|

=12|(17i^+8j^11k^)|

=12289+64+121=12474 sq. units.