I am new in this field (junior year) and I have a question may a little lazy for the majority of the forum.
I have a speech signal $ x(t)=0.4\cos(100πt)+0.3\cos(1800πt)+0.2\cos(980πt)$ and I know that the sampling frequency is $F_s=1000$
If I want to find the signal form after sampling the only thing I have to do is replace $t$ with $κT$
$ x(κT)=0.4\cos(100πκT)+0.3\cos(1800πκT)+0.2\cos(980πκT)$ but $T=1/1000$ so $x(k)= 0.4\cos(0.1πκ )+0.3\cos(0.18πκ )+0.2\cos(0.98πκ )$
Is the solution and the notation OK?