MATLAB: How can we plot this sine wave

basiccosine wavehomeworkmatlab.msimulinksinewavesourcewave generation

it was source

sesha - the only difference between this and the usual sine curve is that it is "inverted". Try doing

x = -pi:0.01:pi;
y = -1 * sin(x);
plot(x,y);

and see how the -1 scalar gives you what you are looking for.

"can we plot a sine wave which half wave i.e. positive side only"

Yes. Here's a hint. This produces one full cycle of a sin curve between -pi and pi. You'll want to plot it from 0 to pi.

x = -pi : 0.01 : pi;
y = sin(x);
plot(x,y)
grid on

"can we plot same sine wave in reverse direction from above plot "

I'm not sure what this means. Perhaps you want the section between -pi and 0?

" how can i plot a cosine wave which has a centre on origin "

Hint: use cos() instead of sin().

The answer is either "You cannot", or else "sin(x)", depending what your question is intended to mean.

If you are trying to do operations on continuous functions to infinity, then the only way to do that in MATLAB is to use the symbolic toolbox.