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If |{:(a,,a^(2),,1+a^(3)),(b,,b^(2),,1+b...

If `|{:(a,,a^(2),,1+a^(3)),(b,,b^(2),,1+b^(3)),(c,,c^(2),,1+c^(3)):}|=0` and the vectors
`vecA =(1, a, a^(2)) , vec(B) = (1, b, b^(2)) , vec(C )(1,c,c^(2))`
are non-coplanar then the product abc = ….

Text Solution

Verified by Experts

The correct Answer is:
-1

Since `|{:(a,,a^(2),,1+a^(3)),(b,,b^(2),,1+b^(3)),(c,,c^(2),,1+c^(3)):}|=0`
`rArr |{:(a,,a^(2),,1),(b,,b^(2),,1),(c,,c^(2),,1):}|+ |{:(a,,a^(2),,a^(3)),(b,,b^(2),,b^(3)),(c,,c^(2),,c^(3)):}|=0`
`rArr (1+abc) |{:(1,,a,,a^(2)),(1,,b,,b^(2)),(1,,c,,c^(2)):}|=0`
`rArr " Either " (1+abc )= 0 " or " |{:(1,,a,,a^(2)),(1,,b,,b^(2)),(1,,c,,c^(2)):}|=0`
But `(1,a,a^(2)) , (1,b,b^(2)), (1,c,c^(2))` are non -coplanar
`rArr |{:(1,,a,,a^(2)),(1,,b,,b^(2)),(1,,c,,c^(2)):}| ne 0`
`:. abc=1`
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