# Sketch the following Signal: $x(t)=3\sin(\frac{\pi t}{4})$ [closed]

I feel kind of overwhelmed by it, and would like someone to walk me through the steps of sketching the signal.

## closed as unclear what you're asking by Marcus Müller, Matt L., lennon310, A_A, Peter K.♦Dec 19 '18 at 14:20

Please clarify your specific problem or add additional details to highlight exactly what you need. As it's currently written, it’s hard to tell exactly what you're asking. See the How to Ask page for help clarifying this question. If this question can be reworded to fit the rules in the help center, please edit the question.

• This is just asking how to plot a function. I'm really not sure whether this is on-topic here; do you know how to plot a function? – Marcus Müller Dec 18 '18 at 11:50

From your physics knowledge you get that sine waves are usually equated, in the general case, as

$$y(t) = A * \sin(\omega t)$$

where $$\omega = 2 \pi f$$ and the periodicity is $$T=1/f$$

Comparing the general equation with your particular case, you have: $$2*\pi*f = \pi / 4$$ meaning that $$f=1/8 Hz$$ or $$T=1/f=8s$$ The amplitude is $$A=3$$

If you want to plot it in matlab, for example, just write

t = 0:0.01:16;
x = 3*sin(pi*t/4);
plot(x,t)


As a final comment, this is really a basic question and you should carefully read your textbook if you want to progress to more advanced topics.

• The period of your signal $y(t)$ isn't $2\pi$, but it is $1/f$. – Matt L. Dec 18 '18 at 12:23
• I've just updated the answer. Thank you for the heads-up Matt. – Filipe Pinto Dec 21 '18 at 10:12