Typically one would start using the first formula to eliminate all possible products sin(Ax)cos(Ax) and then use the other two on all powers that are left. Roughly speaking, these identities allow us to halve powers in exchange for doubling arguments.
In the end we are left with products of the form f(Ax)g(Bx) with A  B, where the above identities do not help. But we have another set of identities handling exactly this case:

Example:

The existing education system

educatin system light up the society with adequate moral changes. that is focus of the education. now everything have been trying into commercial. even let we see the conflict in publishing books. what if the same get going as it now. nothing would change.
let we fight for moderate change in education