Question

If x is equal to 5 - 2 under root 6 find x square + x upon x 2

Answer 1

Answer:

x² + 1/x² = 98

Explanation:

It is given that,

i ) x = 5 -2√6 -----(1)

ii) 1/x = 1/(5-2√6)

= (5+2√6)/[(5-2√6)(5+2√6)]

= (5+2√6)/[5²-(2√6)²]

= (5+2√6)/(25-24)

= 5+2√6 ---(2)

iii) x + 1/x

= 5-2√6+5+2√6

= 10 ----(3)

Now ,

x² + 1/x²

= (x+1/x)² - 2

= 10² - 2

= 100 - 2

= 98

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