GATE 2014 CS (CS1) – Question 4
If $(z+1/z)^2=98$, compute $z^2+1/z^2$.
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Show answer and explanation
Correct answer: 96 to 96
Explanation
Expand(z+1/z)²=z²+2+1/z², with z nonzero as required by the given expression. Subtracting2 from98 gives **96**. This avoids solving for z, since the requested expression is directly determined.