Find x² + 1/x²

Question:

If \[ x+\frac{1}{x}=3 \] find:

\[ x^2+\frac{1}{x^2} \]

Solution:

Using identity:

\[ \left(x+\frac{1}{x}\right)^2 = x^2+\frac{1}{x^2}+2 \]

Substituting the given value:

\[ (3)^2 = x^2+\frac{1}{x^2}+2 \]

\[ 9 = x^2+\frac{1}{x^2}+2 \]

\[ x^2+\frac{1}{x^2} = 9-2 \]

\[ =7 \]

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