Find a² + 1/a²

Question:

If \[ a+\frac{1}{a}=-2 \] find:

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

Solution:

Using identity:

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

Substituting the given value:

\[ (-2)^2 = a^2+\frac{1}{a^2}+2 \]

\[ 4 = a^2+\frac{1}{a^2}+2 \]

\[ a^2+\frac{1}{a^2} = 4-2 \]

\[ =2 \]

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