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Monday, August 11, 2008

Q) Solve for x:
x^2 + [x^2/(x^2 + 1)] = 3


A)
x^2 + [x^2/1+x^2 = 3
x^4 - x^2 = 3
x^2(x^2 - 1) = 3
Let x^2 = y .....thus x = root y
y(y-1)=3
y^2 - y - 3 = 0
y = 1+- root(1 + 12) / 2
y = 1 +-rt(13) /2
now x = root y
so x = root (1 + rt(13) / 2)
other value of y is truncated since x cannot be negative due to root.

x = root [ (1 + rt(13) ) / 2]

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