Solve. Leave in simplest radical form. x^2 - x - 1 = 0?

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Solve. Leave in simplest radical form. x^2 - x - 1 = 0?

2007-05-15 16:58:05 · 4 answers · asked by cyana101 1 in Science & Mathematics ➔ Mathematics

4 answers

[1 +- sqrt(5)] / 2

2007-05-15 17:02:01 · answer #1 · answered by ? 6 · 0⤊ 0⤋

x=1

2007-05-16 00:16:58 · answer #2 · answered by Anonymous · 0⤊ 0⤋

The old "golden mean" equation. The other folks have the solution, so I won't bother you with doing it again. The positive root you wind up with is one of maths "magic number", such that if the number is A, 1/A = A-1. If this sounds a bit far fetched, consider the conversion between miles and km (1.62) and km and miles (0.62).

2007-05-16 00:18:15 · answer #3 · answered by cattbarf 7 · 0⤊ 0⤋

ax^2+bx+c=0

x = [ -b +/- â(b^2 - 4ac) ] / 2a

x = { -(-1) +/- â[(-1)^2 - 4(1)(-1)] } / 2(1)

x = [ 1 +/- â5 ] / 2

2007-05-16 00:04:21 · answer #4 · answered by Anonymous · 1⤊ 0⤋