Here is my code. I do not understand why it does not work. Please help me.
NDSolve[
{Derivative[1][x][t] == -x[t],
Derivative[1][y][t] == x[t] - y[t]^2,
Derivative[1][z][t] == y[t]*y[t],
y[0] == z[0] == 0, x[0] == 1},
{x, y, z}, {t, 0, 5}]
The error I am seeing is:
NDSolve::deqn: Equation or list of equations expected instead of True in the first argument {True,True,True,True,True}.
Clear[x, y, z, Derivative]and try again. – Carl Woll Dec 02 '19 at 03:37