resolve in matlab please

i am new in matlab and i don't have any idea about it. the professor gave us this. really i don't understand. :(

arryf A , s=cosAt+cos3t

define a sum of cosine waves"number of waves is the last number in your credit book. with different frequency en Hz.

2. build it's plot in time domain.

3. build the plot of it's magnitude spectrum

[Walter Roberson]

I do not know what "arryf A" is intended to mean?

[Abdelrazzak rifai]

please if you can give me an example a function using array.

define a sum of cosine waves"number of waves is the last number in your credit book. with different frequency en Hz.

build it's plot in time domain.

build the plot of it's magnitude spectrum

please if you can give me an example about this task. if you have any idea, exampls,etc,,

Answer 1

[Walter Roberson]

number_of_samples = 1025;
wave = 0;
for wavenum = 1 : 8    %presuming your last number is 8
  wave = wave + generate_sinewave(wavenum * 83, number_of_samples);    %83 Hz apart
end

You would need to write generate_sinewave()