Question
Question: If the given vectors \(( - bc,b^{2} + bc,c^{2} + bc),\) \((a^{2} + ac, - ac,c^{2} + ac)\) and \((a^...
If the given vectors (−bc,b2+bc,c2+bc),
(a2+ac,−ac,c2+ac) and (a2+ab,b2+ab,−ab) are coplanar, where none of a, b and c is zero, then
A
a2+b2+c2=1
B
bc+ca+ab=0
C
a+b+c=0
D
a2+b2+c2=bc+ca+ab
Answer
bc+ca+ab=0
Explanation
Solution
Accordingly, $\left| \begin{matrix}
- bc & b^{2} + bc & c^{2} + bc \ a^{2} + ac & - ac & c^{2} + ac \ a^{2} + ab & b^{2} + ab & - ab \end{matrix} \right| = 0$
⇒(ab+bc+ca)3=0⇒ab+bc+ca=0.