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Trapping √2 Between Rationals

Finding rational approximations to irrational numbers

012x = 1.250x+ε = 1.500√2 ≈ 1.414k/q where (k/q)² < 2k/q where (k/q)² > 2x (largest with x² < 2)x + ε (has (x+ε)² > 2)√2 (irrational)

Current Values:

Grid spacing:1/4 = 0.2500
√2 ≈1.414214
x = 1.2500with x² = 1.562500 < 2 ✓
x + ε = 1.5000with (x+ε)² = 2.250000 > 2 ✓

Key insight

As you increase q, the grid becomes finer, and x gets closer to √2 from below. For any ε = p/q, we can always find such an x because we're choosing the largest grid point whose square is still less than 2.