2021 · Q72
If x + 1/x = 8, then what is x² + 1/x² equal to?
Elementary MathematicsAlgebra
- A52
- B46
- C62
- D0
Explanation
Squaring both sides: (x + 1/x)² = x² + 1/x² + 2 = 64. Subtracting 2 from both sides gives x² + 1/x² = 62. Hence option C.
If x + 1/x = 8, then what is x² + 1/x² equal to?
Explanation
Squaring both sides: (x + 1/x)² = x² + 1/x² + 2 = 64. Subtracting 2 from both sides gives x² + 1/x² = 62. Hence option C.