# How would I plot a sin wave.

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Nicholas Deosaran on 17 Sep 2020
Answered: Sai Sri Pathuri on 22 Sep 2020
Hey all how would this be coded?
For a period of 10 seconds and an amplitude of 1 meter, develop a variable that consists of a sine wave of 2 periods where data are determined every tenth of a second.
i have an idea like this
t = [0:1/10:10];
y = 2*sin(t);
plot (t,a)
But I dont know if that is corrent
Hello, the full sine wave function is
sinW = a * sin(2*pi*f*t + theta)
% a is amplitude
% f is frequency
% t is time
% theta is the angle offset
Your answer is mainly correct, but it is missing the 2*pi. You should also probably increase your sampling rate to 1:1/1000:10 to get a better resolution in your plot.
For period of 10 seconds, f =1/10 or f=0.1 in the above equation.

Sai Sri Pathuri on 22 Sep 2020
Since you want to plot a sine wave of 2 periods in a time of 10 seconds, the time period of sine wave must be 5.
freq = 1/5;
sineWave = sin(2*pi*freq*t);
As amplitude required is 1, you need not multiply the sine wave with any coefficient. Hence, sineWave variable defined above is suffice. You can plot it as
plot(t,sineWave)