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Find two positive real numbers that difffer by 1 and have a product of 1

2007-09-30 12:25:13 · 2 answers · asked by plplz 1 in Science & Mathematics Mathematics

2 answers

xy =1
x-y =1
y^2+y-1 = 0
y = [-1 +/- sqrt(5)]/2
y = -.5 +.5sqrt(5)
x = 1 - ( -.5 +.5sqrt(5)) = 1.5 -.5sqrt(5)

2007-09-30 12:55:14 · answer #1 · answered by ironduke8159 7 · 0 0

Form a quadratic equation.

Let the numbers be n and n+1

Then n (n+1) = 1
n^2 + n = 1
n^2 + n - 1 = 0

Use the quadratic formula and you will end with
n = -1.62 or n= 0.62 to 2 decimal places

Ans. would be -1.62 and -.62
or ans. would be .62 and 1.62

2007-09-30 19:43:50 · answer #2 · answered by linz 2 · 0 0

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