i want to add 2 signals with different freq.

i have this SCREW (t)=A0*cos(PHI0*t)+A1*cos(PHI1*t)+A2*cos(PHI2*t)+A3*cos(PHI3*t); the result always A0*cos(PHI0*t) only if i go like this SCREW (t)=A1*cos(PHI1*t)+A2*cos(PHI2*t)+A3*cos(PHI3*t); the result will be A1*cos(PHI1*t)

why cant get the addition of these signals in my matlab code?

[Adam]

You need to show some actual Matlab code. I don't really understand what you are asking, but if you mean there should be more terms than just the first contributing to the result then it is clearly something to do with the definitions of A1, A2, A3, PHI1, PHI2, PHI3, etc which we don't know anything about.

[ihab]

ok its like this A0,A1,A2,A3 IS VALUES

PHI0 = 2*pi*f0/fs; PHI1 = 2*pi*f1/fs; PHI2 = 2*pi*f2/fs; PHI3 =2*pi*f3/fs; for t = 1:fs

 SCREW (t)=A0*cos(PHI0*t)+A1*cos(PHI1*t)+A2*cos(PHI2*t)+A3*cos(PHI3*t);

[KSSV]

YOu have to mention f0,f1,f2,f3,fs,A0,A1,A2,A3 values. Then we can comment why your code is not running.