Question
Functions P(x),Q(x),R(x) are differentiable on some open interval around 0 and satisfy the below equations as well as the initial conditions.
P′(x)=2P2(x)Q(x)R(x)+1Q(x)R(x), P(0)=1
Q′(x)=P(x)Q2(x)R(x)+4P(x)R(x), Q(0)=1
R′(x)=3P(x)Q(x)R2(x)+1P(x)Q(x), R(0)=1.
Then P(x)Q(x)R(x)=tan(nx+π4). The value of n is