1; Find" X - 1/X - Mathematics | Shaalaa.com" /> 1; Find" X - 1/X " /> 1; Find" X - 1/X, Expansion of Formula" />
English

If X^2 + 1/X = 3 1/3 "And X > 1; Find" X - 1/X - Mathematics

Advertisements
Advertisements

Question

If `[x^2 + 1]/x = 3 1/3  "and x > 1; Find If" x - 1/x`

Sum

Solution

Given `[x^2 + 1]/x = 3 1/3`

`[x^2 + 1]/x = 10/3`

`[x + 1/x] = 10/3`

Squaring on both sides, we get

`x^2 + 1/x^2 + 2 = 100/9`

`x^2 + 1/x^2 = [ 100 - 18 ]/9 = 82/9`

`x - 1/x = sqrt[( x + 1/x )^2 - 4] = sqrt( 100/9 - 4 ) = sqrt( 64/9) = 8/3`

∴ `x - 1/x = 8/3`

shaalaa.com
Expansion of Formula
  Is there an error in this question or solution?
Chapter 4: Expansions (Including Substitution) - Exercise 4 (D) [Page 65]

APPEARS IN

Selina Concise Mathematics [English] Class 9 ICSE
Chapter 4 Expansions (Including Substitution)
Exercise 4 (D) | Q 14.1 | Page 65
Share
Notifications

Englishहिंदीमराठी


      Forgot password?
Use app×