Math, asked by jai199, 1 year ago

X square + 1 / x square is equals to 51 find x

Answers

Answered by Anonymous
1
Heya

Question\:Correction:- x^2 + ( 1/x^2) = 51 . Find\: x^3+ 1/x^3

Solution :-

x^2 + ( 1/x^2) = 51

 ( x + 1/x )^2 + 2 ( x ) ( 1/x ) = 51

 ( x + 1/x )^2 + 2 = 51

 (x + 1/x )^2 = 51 - 2

 (x + 1/x )^2 = 49

 x + 1/x = √49

 x + 1/x = 7

Now,
As\:we\:know,

a^3 - b^3 = (a-b)(a^2+ab+b^2)

So x^3-1/x^3

= (x - 1/x)(x² + x × 1/x + 1/x²)

 = (x-1/x)(x^2+1+1/x^2)

=7×(51+1)

 =7 × 52

=364

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