(cos П/8 + sin П/8)^2

Question

(cos П/8 + sin П/8)^2

Answer 1

(sinπ/8+cosπ/8)²=(sinπ/8)²+2*(sinπ/8)*(cosπ/8)+(cosπ/8)²=
=sin²π/8+cos²π/8+sin(2*(π/8))=1+sinπ/4=1+√2/2=(2+√2)/2