Câu 1 đề 1 syms x y a=input(''''nhap a ''''); b=input(''''nhap b ''''); z=(x^2)/(a^2)+(y^2)/(b^2); t=linspace( 5,5); [x,y]=meshgrid(t,t); z=char(z);z=strrep(z,''''*'''','''' *'''');z=strrep(z,''''^'''','''' ^''''); z=eval(z); set(surf(x[.]
Trang 1sA=eval(A);sB=eval(B);sC=eval(C); %tim A,B,C
delta=(sA*sC-sB^2); %tinh delta
elseif sA < 0 % A > 0 la cuc dai
disp('cuc dai la: ')
cd=[cd;a(i) b(i)]
disp(' gia tri cuc dai la: ')
Trang 2câu 2 đề 2
Trang 3Lxx=diff(Lx,'x');Lyy=diff(Ly,'y');Lxy=diff(Lx,'y'); %dao ham cap 2
phix=diff(phi,'x');phiy=diff(phi,'y'); %dao ham dieu kien
for i=1:length(m) %xet cuc dai, cuc tieu
if m(i)==inf || n(i)==inf || l(i)==inf
Trang 6if a>subs(f,[x y],[x0+0.12 y0+0.12])
disp(['GTLN f(' num2str(A(1,2)) ',' num2str(A(1,3)) ')= '
Trang 8sA=eval(A);sB=eval(B);sC=eval(C); %tim A,B,C
delta=(sA*sC-sB^2); %tinh delta
elseif sA < 0 % A > 0 la cuc dai
disp('cuc dai la: ')
Trang 10if a>subs(f,[x y],[x0+0.12 y0+0.12])
disp(['GTLN f(' num2str(A(1,2)) ',' num2str(A(1,3)) ')= '
num2str(A(1,1))])
Trang 11%Ve mat cong:
syms x y z phi teta
Trang 12Lxx=diff(Lx,'x');Lyy=diff(Ly,'y');Lxy=diff(Lx,'y'); %dao ham cap 2
phix=diff(phi,'x');phiy=diff(phi,'y'); %dao ham dieu kien
for i=1:length(m) %xet cuc dai, cuc tieu
if m(i)==inf || n(i)==inf || l(i)==inf
continue
end
Trang 15sA=eval(A);sB=eval(B);sC=eval(C); %tim A,B,C
delta=(sA*sC-sB^2); %tinh delta
elseif sA < 0 % A > 0 la cuc dai
disp('cuc dai la: ')
Trang 16z=eval(z);
set(surf(x,y,z),'FaceColor','g','FaceAlpha','0,3','EdgeColor','g');plot3(a1,b1,c1,'color','r','marker','o','MarkerSize', 20);
%Ve mat cong S:
%Vat the gioi han boi duong 0<=z<=sqrt(x^2+y^2) va x^2+y^2<=1
Trang 18disp('phuong trinh mat tiep dien là: ')
3
Trang 19sA=eval(A);sB=eval(B);sC=eval(C); %tim A,B,C
delta=(sA*sC-sB^2); %tinh delta
elseif sA < 0 % A > 0 la cuc dai
disp('cuc dai la: ')
Trang 20f=z-y^2;
n=[diff(f,'x') diff(f,'y') diff(f,'z')];
n=n/sqrt(diff(f,'x')^2 + diff(f,'y')^2 + diff(f,'z')^2);
%phuong phap tinh la phuong phap stokes
% chuyen ve tich phan mat loai 2
syms r phi real
x=r*cos(phi);y=r*sin(phi); % chuyen sang phuong phap truc toa do
f=eval(f);
I=int(int(f*r,'r',0,1),'phi',0,2*pi)
%Vat the gioi han boi z=y^2,x^2+y^2=1,0=<z<=x^2+y^2
%Ve mat tru parapol z=y^2 phan nam trong mat tru tron xoay
Trang 21Lxx=diff(Lx,'x');Lyy=diff(Ly,'y');Lxy=diff(Lx,'y'); %dao ham cap 2
phix=diff(phi,'x');phiy=diff(phi,'y'); %dao ham dieu kien
for i=1:length(m) %xet cuc dai, cuc tieu
if (dL > 0 && isreal(m(i)))%dao ham cap 2 > 0 => cuc tieu
disp([' diem (' num2str(m(i)) ',' num2str(n(i)) ',' num2str(z) ') la diem cuc tieu'])
elseif (dL < 0 && isreal(m(i))) %dao ham cap 2 < 0 => cuc dai
disp([' diem (' num2str(m(i)) ',' num2str(n(i)) ',' num2str(z) ') la diem cuc dai'])
Trang 22n=[diff(f,'x') diff(f,'y') diff(f,'z')];
n=n/sqrt(diff(f,'x')^2 + diff(f,'y')^2 + diff(f,'z')^2);
%phuong phap tinh la phuong phap stokes
% chuyen ve tich phan mat loai 2
syms r phi real
x=r*cos(phi)-1;y=r*sin(phi); % chuyen sang phuong phap toa do cuc
f=eval(f);
I=int(int(f*r,'r',0,sqrt(3)),'phi',0,2*pi)
%Vat the gioi han boi mat phang 2x+z=2 va mat paraboloid z=x^2+y^2
%Ve mat phang 2x+z=2 nam trong mat Paraboloid
Trang 23%Ve mat paraboloid z=x^2+y^2