deSolve(60*x''+1500*x=90*sin(2.5*t) and x(0)=0 and x'(0)=0,t,x) 를 입력시 x=−0.04*sin(5.*t)-5242.88*sin(t)*(((sin(t))^(2)-0.25)*(cos(t))^(2)-0.0625)*((sin(0.5*t))^(2)+2.75)*(cos(0.5*t))^(13)+5242.88*cos(t)*(((sin(t))^(2)+0.25)*(cos(t))^(2)-0.3125)*sin(0.5*t)*((sin(0.5*t))^(2)+2.25)*(cos(0.5*t))^(12)-29491.2*sin(t)*(((sin(t))^(2)-0.25)*(cos(t))^(2)-0.0625)*((sin(0.5*t))^(2)-0.23611111111111)*(cos(0.5*t))^(9)+21626.88*cos(t)*(((sin(t))^(2)+0.25)*(cos(t))^(2)-0.3125)*sin(0.5*t)*((sin(0.5*t))^(2)-0.375)...