Using parallel circuit rules and Q,V,and C relationships, prove that Ct=C1+C2 for parallel capacitors. need at least a paragraph for an answer!
Both replys from hgmjr's link & Ratch are good,if it will help I'll add some words. Prove the sum of individual caps. in parallel = to a single cap. C. As a given charge[Q] =CV, using two caps. C1 & C2 the charge on each is Q1=C1*V , Q2= C2*V, Q= Q1+Q2 or C1*V+ C2*V=CV; as caps are in parallel then all V's are the same, dividing by V gives: C1+C2=C