Why does Solve give me no solutions for this in Version 8.0.1?
- To: mathgroup at smc.vnet.net
- Subject: [mg119941] Why does Solve give me no solutions for this in Version 8.0.1?
- From: Phil J Taylor <xptaylor at gmail.com>
- Date: Thu, 30 Jun 2011 20:40:24 -0400 (EDT)
This system of equations for the Magic Hexagon is indeterminate. Solve still provides useful information in Version 6.0 ClearAll[a, b, c, d, e, f, g, h, i, j, k, l, m, n, o, p, q, r, s]; eqns = { a + b + c + d + e + f + g + h + i + j + k + l + m + n + o + p + q + r + s - 190 == 0, a + b + c - 38 == 0, a + d + h - 38 == 0, a + e + j + o + s - 38 == 0, b + e + i + m - 38 == 0, b + f + k + p - 38 == 0, c + f + j + n + q - 38 == 0, c + g + l - 38 == 0, d + e + f + g - 38 == 0, d + i + n + r - 38 == 0, g + k + o + r - 38 == 0, h + i + j + k + l - 38 == 0, h + m + q - 38 == 0, l + p + s - 38 == 0, m + n + o + p - 38 == 0, q + r + s - 38 == 0 }; Join[ Solve[eqns, b], Solve[eqns, d], Solve[eqns, g], Solve[eqns, m], Solve[eqns, p], Solve[eqns, j], Solve[eqns, r], Solve[eqns, e], Solve[eqns, f], Solve[eqns, i], Solve[eqns, k], Solve[eqns, n], Solve[eqns, o], Solve[eqns, a], Solve[eqns, c], Solve[eqns, h], Solve[eqns, l], Solve[eqns, q], Solve[eqns, s]] Out[1]: {{b -> j + n + o}, {d -> j + k + o}, {g -> i + j + n}, {m -> f + j + k}, {p -> e + i + j}, {j -> -38 + d + g + r}, {r -> -38 + h + l + m + p}, {e -> -38 + h + k + q + r}, {f -> -38 + i + l + r + s}, {i -> -38 + f + p + q + s}, {k -> -38 + e + m + q + s}, {n -> -38 + g + h + k + l}, {o -> -38 + d + h + i + l}, {a -> -38 + i + m + n + q + r}, {c -> -38 + k + o + p + r + s}, {h -> -38 + n + o + p + r + s}, {l -> -38 + m + n + o + q + r}, {q -> -38 + g + k + l + o + p}, {s -> -38 + d + h + i + m + n}} Version 8.0.1 returns {}.