MathCheck Equation Problem 2 (intro version)

Solve `frac(mu^4 + mu^3 - mu^2)(mu^2 + 3mu) = 0`.

equation mu = (-1+sqrt(5))/2 \/ mu = (-1-sqrt(5))/2 ends f_nodes 19 (mu^4 + mu^3 - mu^2)/(mu^2 + 3mu) = 0 <=> mu != 0 /\ (mu^3 + mu^2 - mu)/(mu + 3) = 0 <=> mu != 0 /\ mu (mu^2 + mu - 1)/(mu + 3) = 0 /**/ <=> mu != 0 /\ (mu = 0 \/ mu = -1/2 + sqrt(1/4 +1) \/ mu = -1/2 - sqrt(1/4 +1)) /**/ <=> mu = -1/2 + sqrt(5)/2 \/ mu = -1/2 - sqrt(5)/2 /**/ <=> mu = (-1 + sqrt(5))/2 \/ mu = (-1 - sqrt(5))/2