(sin22* cos8*+cos158* cos98*): (sin23* cos7*+cos157*cos97*)

Question

(sin22* cos8*+cos158* cos98*): (sin23* cos7*+cos157*cos97*)

Answer 1

(Sin22*cos8+cos158*cos98): (sin23*cos7+cos157*cos97)=
=(sin22*cos8+cos(180-22)*cos(90+8)):(sin23*cos7+cos(180-23)*cos(90+7)=
=(sin22cos8-cos22*sin8):(sin23*cos7- cos23*sin7)=sin30: sin30=1