Some proofs have a few ways of doing them, are more than one method accepted? For example proving that Sin^2A + Cos^2A =1 can be done using a right angled triangle, or using the formula in the log tables (SinASinB+CosACosB= Cos(A-B)) and it can be done finding the distance from the origin to a point(CosA,SinA). Are all three methods accepted?