%书上P129页第三题
a=[49];
c=[49];
b=[50];
f=[50];
for i=1:50
b(i)=4;
f(i)=3;
end
for i=1:49
a(i)=1;
c(i)=1;
end
u(1)=c(1)/b(1);
y(1)=f(1)/b(1);
for i=2:49
u(i)=c(i)/(b(i)-a(i)*u(i-1));
end
for i=2:49
y(i)=(f(i)-a(i)*y(i-1))/(b(i)-a(i)*u(i-1));
end
u
y
x(50)=f(50)/b(50);
for i=49:-1:1
x(i)=y(i)-u(i)*x(i+1);
end
x
