JEE Advance - Mathematics (1987 - No. 1)
If the vectors $$a\widehat i + \widehat j + \widehat k,\,\,\widehat i + b\widehat j + \widehat k$$ and $$\widehat i + \widehat j + c\widehat k$$
$$\left( {a \ne b \ne c \ne 1} \right)$$ are coplannar, then the value of $${1 \over {\left( {1 - a} \right)}} + {1 \over {\left( {1 - b} \right)}} + {1 \over {\left( {1 - c} \right)}} = ..........$$
$$\left( {a \ne b \ne c \ne 1} \right)$$ are coplannar, then the value of $${1 \over {\left( {1 - a} \right)}} + {1 \over {\left( {1 - b} \right)}} + {1 \over {\left( {1 - c} \right)}} = ..........$$
0
1
2
-1
None of these