Every signal consists of mathematical function with certain variables. Such variables are amplitude, frequency, sampling time etc. For example well known signal function of sine wave whose mathematical function is a*sin(w*t) is a combination of above mentioned variables.
Few well known wave form equations are
Sine wave y = A.sin(ωt + φ)
Sawtooth wave 
Square wave 
Triangle wave 
The default written formulas in this experiment are
1. a*sin(w*t)+5*(rand(-1)-0.5)......................................random noise
2. 10*t/fs.....................................................................ramp function
3. a*sin(w*t)+cos(w*t).................................................addition of sine and cosine
4. a*sin(w*t+pi(1))*(a-sin((w*t)+pi(1)/4))).....................arbitary function
