Plotting Sinusoidal Wave Graph on MatLab

I want to plot the graph of this sinusoidal equation on matlab but I could not accomplished right...

Here is my sinusoidal wave equation:

v(t) = 5cos(1256t - pi/4)

Answer 1

[William Rose]

@cikalekli,

Start by figuring out a good time range. Since you have cos(1256t-pi/4), the period is , so let's plot for two periods, i.e. time=0 to 0.01:

t=0:.0005:0.01;         %create vector of time values, with step size=0.0005
x=5*cos(1256*t-pi/4);   %compute x(t)
plot(t,x,'r.-')         %plot

Try it.

[cikalekli]

Thanks a lot, you are very well demonstrated your answer.

[cikalekli]

My qustion is, the curves are still looks too sharp. How can I plot it with a smooth shape please?

[William Rose]

@cikalekli, Make the time step size smaller. Try 0.0001, insead of 0.0005 previously:

t=0:.0001:0.01;         %create vector of time values, with step size=0.0001
x=5*cos(1256*t-pi/4);   %compute x(t)
plot(t,x,'r.-')         %plot

[cikalekli]

Now I got it how can I approach this form. You are truly perfect... Thank you a lot again

[William Rose]

You're welcome, cikalekli.