help with numerical analysis
2 vues (au cours des 30 derniers jours)
Afficher commentaires plus anciens
if true
fplot('pi*x*sqrt((x)^2+((750/pi)^2)/(x)^4)',[0,10]);
[R fmin]=fminbnd('pi*x*sqrt((x)^2+((750/pi)^2)/(x)^4)',0,8);
h=170/(pi*R^2);
grid on
fprintf('The Value of R is %5.4f cm and the Height is %5.4f cm\n',R,h)
end
a paper cup shaped as a cone is designed to have a volume of 250cm^3. Determine the radius R and height h such that the least amount of paper will be used for making cup my answers came up as
Value of R is 5.5267 cm and the Height is 1.7716 cm but the book says is Value of R is 6.9632cm and the height is 4.9237 any advice or any mistakes that you can point out, thanks
0 commentaires
Réponse acceptée
Andrei Bobrov
le 24 Juil 2013
Modifié(e) : Andrei Bobrov
le 24 Juil 2013
syms R H V real
H = 3*V/(pi*R^2);
S = subs(pi*R*sqrt( R^2/4+H^2 ),V,250);
Rout = double(solve(diff(S,R),R));
Rout = Rout(Rout>0&imag(Rout)==0)
Hout = double(subs(H,{V,R},{250,Rout}))
OR
[R fmin]=fminbnd(@(x)pi*x.*sqrt(x.^2/4+(750/pi)^2./x.^4),0,8)
Plus de réponses (1)
Raghavendra
le 24 Juil 2013
Basically the equation for cone says Volume(V)= (Pi*r*r*h)/3; You have two unknown variable, Lets assume the radius = 2, then you can use this formula to find out the Height.
0 commentaires
Voir également
Catégories
En savoir plus sur Polynomials dans Help Center et File Exchange
Community Treasure Hunt
Find the treasures in MATLAB Central and discover how the community can help you!
Start Hunting!