Sinusoidal curves forms and linspace, anything to do with Nyquist frequency?

Question

I was playing around with sinusoidal curves and saw this:

I defined an array of numbers between 0 and $2\pi$ with 200 points.

x=np.linspace(0, np.pi, 200)

Then I went on to plotting the following curve by varying the frequecies:

plt.plot(x, 2*np.sin(20*x))

$sin(20x)$

plt.plot(x, 2*np.sin(80*x))

$sin(80x)$

plt.plot(x, 2*np.sin(100*x))

$sin(100x)$

plt.plot(x, 2*np.sin(200*x))

$sin(200x)$

plt.plot(x, 2*np.sin(300*x))

$sin(300x)$

plt.plot(x, 2*np.sin(600*x))

$sin(80x)$

and finally one more,

plt.plot(x, 2*np.sin(600000*x))

$sin(600000x)$

Can anyone please tell me why are these strange patterns emerging, and is there any name for this phenomenon? I can guess that it is in some way related to the Nyquist frequency, but I would like someone to please expound the matter. Also is there any equation which can predict the shape of the curves for any multiples of the input frequency?

BTW, This is how the original signal looks:

$sin(x)$