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If M 2 + 1 M 2 = 51 ; Find the Value of M 3 − 1 M 3 - Mathematics

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प्रश्न

If `"m"^2 + (1)/"m"^2 = 51`; find the value of `"m"^3 - (1)/"m"^3`

योग

उत्तर

`"m"^2 + (1)/"m"^2 = 51`

We know that 
`("m" - 1/"m")^2`

= `"m"^2 + (1)/"m"^2 - 2`

⇒ `("m" - 1/"m")^2` = 51 - 2

⇒ `("m" - 1/"m")^2` = 49 = 72 

⇒ `"m"  - 1/"m"` = 7

⇒ `("m"  - 1/"m")^3` = 73 

⇒ `"m"^3 - (1)/"m"^3 - 3("m" - 1/"m")` = 343

⇒ `"m"^3 - (1)/"m"^3 - 3 xx 7` = 343

⇒ `"m"^3 - (1)/"m"^3`
= 343 + 21
= 364.

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  क्या इस प्रश्न या उत्तर में कोई त्रुटि है?
अध्याय 4: Expansions - Exercise 4.2

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फ्रैंक Mathematics [English] Class 9 ICSE
अध्याय 4 Expansions
Exercise 4.2 | Q 7
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