figure(1)
for n=1:10
    x=-2*pi:0.1:2*pi
    y1=cos(n.*x)
    plot(x,y1)
    hold on
end
x=-2*pi:0.1:2*pi
y=1*ones(1,126)
plot(x,y)
axis([-8,8,-1.5,1.5])
figure(2)
for n=1:10
    x=-2*pi:0.1:2*pi
    y1=sin(n.*x)
    plot(x,y1)
    hold on
end
axis([-8,8,-1.5,1.5])
figure(3)
sum=0
for j=1:3
    sum=sum-((1/(pi.*j)).*(1-((-1).^j))).*sin(j.*x)
end
a=1/2+sum
plot(x,a)
figure(4)
sum=0
for j=1:9
    sum=sum-((1/(pi.*j)).*(1-((-1).^j))).*sin(j.*x)
end
a=1/2+sum
plot(x,a)
figure(5)
sum=0
for j=1:11
    sum=sum-((1/(pi.*j)).*(1-((-1).^j))).*sin(j.*x)
end
a=1/2+sum
plot(x,a)
figure(6)
sum=0
for j=1:3
    sum=sum-(2/j).*sin(j.*x)
end
a=pi+sum
plot(x,a)
figure(7)
sum=0
for j=1:9
    sum=sum-(2/j).*sin(j.*x)
end
a=pi+sum
plot(x,a)
figure(8)
sum=0
for j=1:11
    sum=sum-(2/j).*sin(j.*x)
end
a=pi+sum
plot(x,a)