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If x + 1/x = 2, what is the value of x^2 + 1/x^2 ?

When possible, with explanation please.
Thanks in advance!

2007-10-05 13:23:45 · 6 answers · asked by Anonymous in Science & Mathematics Mathematics

6 answers

x+1/x =2
(x^2+1)/x=2
x^2+1=2x [By cross-multiplication]
x^2-2x+1=0
(x-1)^2=0
x=1
Therefore,x^2+1/x^2
=(1)^2+1/1^2
=1+1=2

2007-10-05 13:30:52 · answer #1 · answered by alpha 7 · 0 0

X+1/X=2

SO x=2

4+1/4= 5/4 =1.25

2007-10-05 13:28:28 · answer #2 · answered by retardedfroggy 1 · 0 0

First, find solution for first equation:

x + 1/x = 2
x^2 + 1 = 2x
x^2 - 2x + 1 = 0 --> this is your quadratic equation, then:
(x -1)^2 = 0
Then : x - 1 = 0
x = 1

Use this answer to second equation:

x^2 + 1/x^2
1^2 + 1/1 ^2
1 + 1 = 2

And that's your value....Ciao

2007-10-05 13:34:24 · answer #3 · answered by mitzbitz 2 · 0 0

x + 1/x = 2

multiply x for both sides
x^2 + 1 = 2x

subtract 2x for both sides
x^2 - 2x + 1 = 0

factor
(x - 1) (x - 1) = 0

(x - 1)^2 = 0

take a square root
x - 1 = 0

add 1 for both sides
x = 1

so 1^2 + 1/1^2 = 1 + 1 = 2 <== answer

2007-10-05 13:29:15 · answer #4 · answered by      7 · 0 0

x + 1/x = 2
x² + 1 = 2x
x² - 2x + 1 = 0
(x - 1)² = 0
x = 1
_______

x² + 1/x² = 1² + 1/1² = 1 + 1 = 2

2007-10-05 13:33:47 · answer #5 · answered by Northstar 7 · 0 0

(1) + 1(1) = 2, so (1)^2 + 1/(1)^2 also equals 2!

2007-10-05 13:28:00 · answer #6 · answered by Anonymous · 0 0

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