syms y(x)
Dy = diff(y);
ode = diff(y,x,2)+ 2*0.15*diff(y,x)+y ==sin(pi*x/5);
cond1 = y(0) == 1;
cond2 = Dy(0) == 0;
ySol(x) = dsolve(ode,cond1,cond2)
ySol(x) =
exp(-(3*x)/20)*sin((391^(1/2)*x)/20)*((10*391^(1/2)*exp((3*x)/20)*((3*sin(x*(pi/5 - 391^(1/2)/20)))/20 - cos(x*(pi/5 - 391^(1/2)/20))*(pi/5 - 391^(1/2)/20)))/(391*((pi/5 - 391^(1/2)/20)^2 + 9/400)) + (10*391^(1/2)*exp((3*x)/20)*((3*sin(x*(pi/5 + 391^(1/2)/20)))/20 - cos(x*(pi/5 + 391^(1/2)/20))*(pi/5 + 391^(1/2)/20)))/(391*((pi/5 + 391^(1/2)/20)^2 + 9/400))) - exp(-(3*x)/20)*cos((391^(1/2)*x)/20)*((25*sin((pi*x)/5 + (391^(1/2)*x)/20)*exp((3*x)/20)*(191*pi*391^(1/2) - 8*391^(1/2)*pi^3))/(391*(4*pi^4 - 191*pi^2 + 2500)) - (25*sin((pi*x)/5 - (391^(1/2)*x)/20)*exp((3*x)/20)*(191*pi*391^(1/2) - 8*391^(1/2)*pi^3))/(391*(4*pi^4 - 191*pi^2 + 2500)) + (50*sin((pi*x)/5 - (391^(1/2)*x)/20)*exp((3*x)/20)*(pi^2 - 25))/(4*pi^4 - 191*pi^2 + 2500) + (50*sin((pi*x)/5 + (391^(1/2)*x)/20)*exp((3*x)/20)*(pi^2 - 25))/(4*pi^4 - 191*pi^2 + 2500) + (75*pi*cos((pi*x)/5 - (391^(1/2)*x)/20)*exp((3*x)/20))/(4*pi^4 - 191*pi^2 + 2500) + (75*pi*cos((pi*x)/5 + (391^(1/2)*x)/20)*exp((3*x)/20))/(4*pi^4 - 191*pi^2 + 25\\\r\n00) + (150*391^(1/2)*cos((pi*x)/5 - (391^(1/2)*x)/20)*exp((3*x)/20)*(pi^2 + 25))/(391*(4*pi^4 - 191*pi^2 + 2500)) - (150*391^(1/2)*cos((pi*x)/5 + (391^(1/2)*x)/20)*exp((3*x)/20)*(pi^2 + 25))/(391*(4*pi^4 - 191*pi^2 + 2500))) + (exp(-(3*x)/20)*cos((391^(1/2)*x)/20)*(150*pi - 191*pi^2 + 4*pi^4 + 2500))/(4*pi^4 - 191*pi^2 + 2500) + (391^(1/2)*exp(-(3*x)/20)*sin((391^(1/2)*x)/20)*(400*pi^3 - 573*pi^2 - 9550*pi + 12*pi^4 + 7500))/(391*(pi*391^(1/2) + 2*pi^2 + 50)*(2*pi^2 - pi*391^(1/2) + 50))