Answers

  • Brainly User
2014-05-15T13:03:55+05:30
The answer will be 14.
as x+1/x=4 
=>given x^2+1/x^2 = (x+1/x)^2 -2
=>(4)^2 -2 
=>16-2 =14.
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x^2+1/x^2+2-2=(x+1/x^2)-2
4^2-2=14
Please can you explain why 2 is subtracted both sides
as (x+1/x)^2 = x^2 +1/x^2 +2(x)(1/x) =16
=>x^2 + 1^2 /x^2 + 2 = 16
=> x^2 +1/x^2 = 16 - 2=14
now u understand mohit
  • Brainly User
2014-05-15T13:09:00+05:30
X+1/x= 4, x^2+ 1/x^2=?
Solution:
x+1/x = 4
Squaring on both sides we get
(x+1/x)^2 = 4^2
x^2 + (1/x)^2 + 2*x*1/x = 16
(
because (a+b)^2 = a^2 +b^2 +2ab

here a=x b=1/x
)

=> x^2 + 1^2 /x^2 + 2 = 16
=> x^2 +1/x^2 = 16 - 2
=> x^2 +1/x^2 = 14

Hope this is helpful.

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