JEE Main 201911 Jan, Morning shiftMathematicsMediumVector Algebra184× since 2002Let a→=i^+2j^+4k^,\overrightarrow a = \widehat i + 2\widehat j + 4\widehat k,a=i+2j+4k, b→=i^+λj^+4k^\overrightarrow b = \widehat i + \lambda \widehat j + 4\widehat kb=i+λj+4k and c→=2i^+4j^+(λ2−1)k^\overrightarrow c = 2\widehat i + 4\widehat j + \left( {{\lambda ^2} - 1} \right)\widehat kc=2i+4j+(λ2−1)k be coplanar vectors. Then the non-zero vector a→×c→\overrightarrow a \times \overrightarrow ca×c is :AOption A. −10i^−5j^- 10\widehat i - 5\widehat j−10i−5jBOption B. −10i^+5j^- 10\widehat i + 5\widehat j−10i+5jCOption C. −14i^+5j^- 14\widehat i + 5\widehat j−14i+5jDOption D. −14i^−5j^- 14\widehat i - 5\widehat j−14i−5jCheckSkip · show solution
