AP EAMCET20228 Jul 2022Morning ShiftMathematicsVector AlgebraActual
A , B , C , D are any 4 points and | A B C D + B C A D + C A B D |= (Area of A B C ) then =
Options
- A1
- B2
- C3
- D4
Correct answer
D. 4
Step-by-step solution
Given four points A, B, C and D with position vectors a , b , c and d respectively. Now | AB CD + BC AD + CA BD |= Area of ABC . aligned & |( b - a ) ( a - c )+( c - b ) ( d - a )+( a - c ) ( d - b )| & 2 | a b + b c + c a | & 2| a b + b c + c a |= 2 | a b + b c + c a | aligned Compare above equation, gathered 2= 2 =4 gathered