Dear Sir; restart; _EnvAllSolutions:=true; eqn1:=cos(omega[1]*t[1])+cos(omega[1]*t[2])=-1; eqn2:=cos(r*omega[1]*t[1])+cos(r*omega[1]*t[2])=-1; solve({eqn1,eqn2},[t[1],t[2]]); I try to get the solutions. It gives me very complicated answer. How do I interpret the results with assumed variables? Actually, I want to get the closed form solution. Could you help me about the problem? Thanks. Sung

Hello! I got a trouble to get the answer of following exponential function with summation. I expect that the answer should be "Heaviside" forms. However, the maple software does not go further. restart; assume(i::posint,n::posint,s::complex); eq1:=sum((-1)^i*exp(-s*T[i])/s,i = 1..n); inttrans[invlaplace](eq1,s,t) assuming T[i]>0,T[i+1]>T[i]; I am a novice for maple. Is there any procedure routine? Please tell me about it. Thanks. Y-G Sung sungyg@chosun.ac.kr