Question

if X equal to root 5 + 2 then prove that X square + 1 upon x square equal to 18​

Answer 1

Answer:

Explanation:

x = √5+2

1/x= 1/√5+2

on rationalize

multiply √5-2 on nominator or denominator

1/x=√5-2/5-4⇒√5 - 2

according to question

x²+(1/x)²

x=√5 +2

x²=5+4+10√5

1/x=√5-2

(1/x)²=5+4-10√5

According to question

5+4+10√5+5+4-10√5⇒18

hence proved.

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