I am solving a problem that involves expanding $\sin(x-x^2)$.
Since $$\sin(x)=x-x^3/6+x^5/120-...$$ i try to substitute $x$ to $x-x^2$ to arrive at expansion of $x-x^2-x^3/6+x^4/2-x^5/2+x^6/6+...$
Now that would be good enough, but if I look up at this expansion on WolframAlpha I see that it is supposed to look like $x-x^2-x^3/6+x^4/2-59x^5/120+x^6/8$
So does that mean that I cannot make that substitution? Where is the mistake?