
*如果需要源文件可以到前文下载

function p=dd(n,x)
syms m;
m=[0,0;0,0]
m(1,:)=randi([1,x],[1,2]);
m(2,:)=randi([1,x],[1,2]);
for i=3:n
m(i,1)=m(i-1,1)+m(i-2,1);
m(i,2)=m(i-1,2)+m(i-2,2)
end
end


function l=dd(a)
if a<=1/2
l=2*a;
else l=2*(1-a);
end

下面为7.2,电子版已删除
function l=dd(a)
syms k;
hold on;
grid on;
k=2;
if a>=(pi/4)
l=1;
elseif a>(-4/pi)
l=atan(a)^k;
else l=-1;
end
syms x;
fplot('dd(x)',[-4,4])


function p=dd(m)
syms t;
t=-m/10:0.01:m/10;
plot3(m*cos(t)/20,m*sin(t)/20,t)
dd(522)

function p=dd(m)
syms t;
t=-m/10:0.01:m/10;
plot3(cos(t)+t.*sin(t),sin(t)-t.*cos(t),-t)
dd(522)


syms x y m
m=522;
ezplot(sin(x^2+m*y^2/1000)==cos(x*y),[-10,10])

function p=dd(f,x,n,m)
p=[x];
for i=2:n
p(i)=f(p(i-1));
end
end
function p=dd(f,x,n,m)
p=[x]
for i=2:n
p(i)=f(p(i-1));
end
end
syms m
m=522;
x= sym(dd(@(x)(x+m/x)/2,3,20,m)); % dd(@(x)(x+m/x)/2,-3,20,m)
fprintf('%.8f\n',x(20))



function mp=map(f,c)
x=[];
y=[];
x(1)=c;
y(1)=0;
x(2)=x(1);
y(2)=f(x(1));
for i=1:100
x(1+2*i)=y(2*i);
x(2+2*i)=x(1+2*i);
y(1+2*i)=x(1+2*i);
y(2+2*i)=f(x(2+2*i));
end
plot(x,y,'r');
hold on;
syms x;
ezplot(x,[-1200,500]);
ezplot(f(x),[-1200,1200]);
axis([0,20,0,20]);
syms m
m=522;
x1=-1200:1:-550;
x2=-450:1:500;
map(@(x)(x+m^2)/(x+m),200)
% 另外一种蛛网图 map(@(x)(x+m^2)/(x+m),200)

function p=dd(f,x,n,m)
p=[x]
for i=2:n
p(i)=f(p(i-1));
end
end
function fcc=fc(ax)
fcc=1-abs(ax-1);
end
syms m
m=522;
for i=0:0.1:2
x=dd(@(x)fc(x),i,20,m);
x(20)
end

hold on;
grid on;
f=inline('2.8*x*(1-x)');%替换为四种α
x0=0.5;
for i=1:0.1:10
plot(i,f(x0),'.')
x0=f(x0);
end

function mar=mart(a,b,c,N)
f=@(x,y)(y-sign(x)*sqrt(abs(b*x-c)));
g=@(x)(a-x);
m=[0;0];
for n=1:N
m(:,n+1)=[f(m(1,n),m(2,n)),g(m(1,n))];
end
plot(m(1,:),m(2,:),'kx');
axis equal
end
mart(522,522,522,10000)
mart(-522,-522,522,10000)
mart(-522,522/1000,-522,10000)
mart(-522/10,17,4,100000)

function p=dd(f,x0,n)
p=[x0];
for i=2:n
p(i)=f(p(i-1));
end
end
m=522;
x=m^(1/3);
a=50;
c=1;
d=0;
(x + 522)/(x + 1)
dd(@(x)((a*x+m*c)/(c*x^2+a)),1,50)
*以下三题为三选一,这里只给出2.9



function p=dd()
sym ct i
ct=0;
i=0;
while double(ct)<2
i=double(i)+1;
n=i;
flag=0;
while (n>0)
if (mod(n,10) ==9)
flag=1;
end
n=floor(n/10);
end
if (flag==1) %若flag==0 则为第二小问
ct=double(ct)+1/i;
end
end
i
end