In my task, I should draw n samples from a two dimensional random variable U=(U1,U2), where U1 and U2 are independent and both uniformly distributed on [-1,1].
Afterwards, I should plot the sample and mark all the samples which fulfill (U1^2 + U2^2)<1. (I already know that the outcome will be a circle with radius r=1.)
To plot the sample I used scatter(U1,U2). How can I color the samples which fulfill the condition (U1^2 + U2^2)<1?