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Statement I cos^(3)alpha+cos^(3)(alpha+(...

Statement I `cos^(3)alpha+cos^(3)(alpha+(2pi)/(3))+cos^(3)(alpha+(4pi)/(3))`
`=3 cos alpha cos (alpha+ (2pi)/(3))cos(alpha+(4pi)/(3))`
Statement II If `a+b+c=0 hArr a^(3)+b^(3)+c^(3)=3abc`

A

`1`

B

`5/2`

C

`3/2`

D

`2`

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statement-I- cos^3alpha + cos^3(alpha+2pi/3) + cos^3(alpha+4pi/3) = 3cosalpha cos(alpha+2pi/3)cos(alpha+4pi/3) Because Statement-II - if a+b+c=0 iff a^3+b^3+c^3=3abc

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