Recent content by Ravik Rocha

I do know the difference between real and virtual images. I would like to know the difference between real and virtual objects. I need some examples. See this picture

Hi people, I have a master degree in mathematics and I hope help you with math.

I'm reading a very general definition of parameter on this site Parameter definition - Math Insight. I didn't understand why we call the variable $t$ of the curve $\alpha(t)=(\cos t,\sin t)$ a parameter. For me $t$ in this case is a variable too according to the definition of the site I...