m = var('m') #eq=function('eq')(m) eq = -cos(m)^4*e^(3*m) - 2*cos(m)^2*e^(3*m)*sin(m)^2 - e^(3*m)*sin(m)^4;show(eq); show(solve(eq==0,m)) show(eq(m=1/2*pi))
#Clearly m= 1/2 *pi is not a root!