how to solve logarithm equation
Afficher commentaires plus anciens
i want to solve an logarithm equation and find the value of x
log10(x^4)-log10(x^3) == log10(5*x) -log10(2*x)
4 commentaires
Davide Masiello
le 11 Oct 2022
Modifié(e) : Davide Masiello
le 11 Oct 2022
I believe that reduces to
and therefore there's no real solution to it
log10(4/3) == log10(5/2)
MANANJAYA NAYAK
le 11 Oct 2022
Ghazwan
le 11 Oct 2022
syms a b c x
eqn = a*x^2 + b*x + c == 0
S = solve(eqn)
David Hill
le 11 Oct 2022
Use fzero to solve a non-linear equation numerically. fzero
Réponse acceptée
Plus de réponses (2)
if you plot, it never crosses zero.
f=@(x)log10(4*x)-log10(3*x) -log10(5*x) +log10(2*x)
fzero(f,1)
log10(4*x)-log10(3*x) = log10((4*x)/(3*x)) = log10(4/3)
log10(5*x)-log10(2*x) = log10((5*x)/(2*x)) = log10(5/2)
So you try to "solve"
log10(4/3) = log10(5/2)
You can imagine that this makes no sense.
Catégories
En savoir plus sur Programming dans Centre d'aide et File Exchange
Community Treasure Hunt
Find the treasures in MATLAB Central and discover how the community can help you!
Start Hunting!
