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If x=5-√21/2,find the value of (1)x+1/x …

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If x=5-√21/2,find the value of (1)x+1/x (2)x²+1/x²

Posted by Rakshith V 5 years, 3 months ago

CBSE > Class 09 > Mathematics

1 answers

Gaurav Seth 5 years, 3 months ago

Step-by-step explanation:

Given ,

x = (5 - √21)/2

1/x = 2/(5 -√21)

=2(5 + √21)/(5 -√21)(5 + √21)

= (5 + √21)/2

hence,

x + 1/x = (5 -√21)/2 + (5+√21)/2 =5

x² + 1/x² = (x + 1/x)² -2x.1/x

= (x + 1/x)² -2

=(5)² -2

= 23

1Thank You

ANSWER

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CBSE > Class 09 > Mathematics