/sci/ - Science & Math

Motion is relative, so why is it not equally correct to say the sun revolves around the earth as to say the earth revolves around the sun? Or to say that neither revolves around the other? Seems there is a causal bias here.

This is not homework. I just want to learn some of your higher maths.

Why does <span class="math">\frac{a}{b} + \frac{c}{d}[/spoiler] not equal <span class="math"> \frac{a + c}{b + d}[/spoiler] ?

How do yuou find the "domain" of a function? Do you have to graph it?

Speed is relative, so if a photon bounces off me and I walk slowly in the other direction, haven't I just surpassed the speed of light, relative to that photon?