# How do I find all the positive roots of (e^(-.2x ))(cos(2x))-.15x^2+1

1 visualizzazione (ultimi 30 giorni)
Rachel il 10 Apr 2013
So far, I've done
fun=@(x) exp^(-.2*x)*cos(2*x)-.15*x^(2)+1;
x0=[-6: .1 :6];
z=fzero(fun,x0);
Nothing happens.
##### 0 CommentiMostra -2 commenti meno recentiNascondi -2 commenti meno recenti

Accedi per commentare.

### Risposte (1)

Seth DeLand il 10 Apr 2013
2 things: 1) fzero is designed to find a single zero at a time. You will need to loop through each value for x0 and record the zero the fzero found for that starting point. Something like:
for i = 1:length(x0)
z(i) = fzero(fun, x0(i));
end
2) exp is a function that expects 1 input, if you want to calculate e^(-.2x) you can write:
exp(-.2*x)
##### 0 CommentiMostra -2 commenti meno recentiNascondi -2 commenti meno recenti

Accedi per commentare.

### Categorie

Scopri di più su Loops and Conditional Statements in Help Center e File Exchange

### Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!

Translated by