I'm having trouble with projectile motion, mainly with understanding which formulas do what. I understand some, others I do not. Here are my formulas: Vx= V cos theta-- I know this is to find x components Vx= V sin theta-- I know this is to find y components tan theta=Ry/Rx-- I know i use my resultant x and y components in these, but I don't know what tan theta is. X=V0t-- I do not understand this formula Its mainly the V0x and V0y that I do not understand. Thank you for your help.