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Solve log equations problem

asked 2012-03-09 12:36:53 +0100

Ticksy gravatar image

Input

var('x')
solve((log((x**2 - x), 6) - log((6*x - 10), 6) == 0), x)

Output

[log(x^2 - x) == log(6*x - 10)]

But real roots are 5 and 2. What I doing wrong?

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answered 2012-03-09 13:42:48 +0100

achrzesz gravatar image

updated 2012-03-09 14:18:45 +0100

kcrisman gravatar image

I have no problems with 5:

sage: solve((log((x**2 - x), 6) - log((6*x - 10), 6) == 0), x,to_poly_solve=True)             

[x == 2, x == 5]
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answered 2012-03-09 12:45:31 +0100

achrzesz gravatar image

solve((log((x*2 - x), 6) - log((6x - 10), 6) == 0), x,to_poly_solve=True)

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Comments

Thank you. It works. But what with root 5? He seemed to be a solution of the original equation ...

Ticksy gravatar imageTicksy ( 2012-03-09 13:21:37 +0100 )edit

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Asked: 2012-03-09 12:36:53 +0100

Seen: 1,097 times

Last updated: Mar 09 '12