how can i plot these signals

hi everybody . i have an image of signal but i want to create it myself for inserting in an article . can anyone help me how can i create it ? sorry for my bad English . any help would be appreciated. http://com-edu.persiangig.com/Capture.PNG

Answer 1

[Dishant Arora]

a)

t=0:.001:1;
f=f(0)+k*t;           // f(0)=initial frequency and K some arbitrary constant
y=sin(2*pi*f.*t);
plot(t,y)

b)

t=0:.00001:1;
A=k*sin(2*pi*t);
y=A.*sin(2*pi*100*t);
plot(t,y)