РЕШИТЕ!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! cos(π- α)+ cos(3π/2+ α)/1+2cos(-α)∙sin(- α) .

Question

РЕШИТЕ!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
cos(π- α)+ cos(3π/2+ α)/1+2cos(-α)∙sin(- α) .

Answer 1

Cos(π-α)+cos(3π/2+α)+2cos(-α)sin(-α)=-cosα+cosα-sin2α= - sin2α