Question

cos(3α-2β)cos(α-2β) + sin(3α-2β)Cos(α-2β)

Answer 1

$cos(a)sin(b)+sin(a)cos(b)=sin(a+b)\cos(3a-2b)sin(a-2b)+sin(3a-2b)cos(a-2b)=\=sin(4a-4b)$