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Question
Find : `"a"^3-1/"a"^3`, if `"a" -1/"a"=4`.
Solution
`"a" -1/"a"=4`
`⇒("a"-1/"a")^3=(4)^3`
`⇒"a"^3-1/"a"^3-3"a"xx1/"a"("a"-1/"a")=64`
`⇒"a"^3-1/"a"^3+3(4)=64` ........`[∵"a"-1/"a"=4]`
`⇒"a"^3-1/"a"^3-12=64`
`⇒"a"^3-1/"a"^3=64+12`
`⇒"a"^3-1/"a"^3=76`
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