KCET2011MathematicsVector Algebra
If 2 i +3 j , i + j + k and i +4 j +2 k taken in an order are coterminous edges of a parallelopiped of volume 2 cu units, then value of is
Options
- A-4
- B2
- C3
- D4
Correct answer
D. 4
Step-by-step solution
Given, let A=2 i +3 j +0 k B= i + j + k C= i+4 j+2 k If A, B, C are the coterminous edges of a parallelopiped then its volume is =(A B) C = (2 i +3 j +0 k ) ( i + j + k ) ( i +4 j +2 k )=(3 i -2 j - k ) ( i +4 j +2 k )=3 -8-2=3 -10 Given volume =2 aligned & & 3 -10 &=2 & & 3 &=12 & &=4 aligned