Exponential inequalities

10102015, 11:58 AM
(This post was last modified: 10102015 12:00 PM by parisse.)
Post: #3




RE: Exponential inequalities
The solver can solve polynomiallike equations/inequations. Unfortunately there is no easy way to reduce all equations/inequations to a polynomial. But most of the time, you can help the CAS by calling the right presimplification command. Here you can do
a:=tsimplify(2^(3*x1)+2^(6*x2)2^(3*x+3)(4^(3*x2)) This will express the inequation in terms of the minimum possible independant "variables", here 1, hence the inequation becomes polynomiallike, then solve(a<0) will return the exact answer. The approx answer is partially wrong because the floats are too small for x negative. Remember: the calc computes very fast but it is stupid, humans do not compute fast but humans know what to do, a typical situation where both can cooperate! 

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Messages In This Thread 
Exponential inequalities  Aries  10092015, 10:54 AM
RE: Exponential inequalities  roadrunner  10102015, 10:35 AM
RE: Exponential inequalities  parisse  10102015 11:58 AM
RE: Exponential inequalities  Aries  10112015, 10:20 AM
RE: Exponential inequalities  Aries  10172015, 09:06 AM
RE: Exponential inequalities  Tim Wessman  10102015, 01:54 PM
RE: Exponential inequalities  Aries  10112015, 06:39 AM
RE: Exponential inequalities  roadrunner  10102015, 11:03 PM
RE: Exponential inequalities  Aries  10112015, 10:23 AM
RE: Exponential inequalities  parisse  10172015, 04:15 PM
RE: Exponential inequalities  Aries  10252015, 10:53 AM

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