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STD 12 - 10. vector algebra — Mathematics STD 12 Science — Question

CBSE BoardEnglish MediumSTD 12 ScienceMathematicsSTD 12 - 10. vector algebra1 Mark
MCQ
If $ a, b, c$  are three non-coplanar vector, then $\frac{{a\,.\,b \times c}}{{c \times a\,.\,b}} + \frac{{b\,.\,a \times c}}{{c\,.\,a \times b}}$=
  • ✓
    $0$
  • B
    $2$
  • C
    $-2$
  • D
    None of these
✓

Answer

Correct option: A.
$0$
a
(a) $\frac{{a.b \times c}}{{c \times a.b}} + \frac{{b.a \times c}}{{c.a \times b}} = \frac{{[a\,b\,c]}}{{[c\,a\,b]}} + \frac{{[b\,a\,c]}}{{[c\,a\,b]}} = \frac{{[a\,b\,c]}}{{[c\,a\,b]}} - \frac{{[a\,b\,c]}}{{[c\,a\,b]}} = 0.$

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