Question

Помогите упростить.
sin2a/2cosa;
cos36°+sin18°/cos^2 18°

Answer 1

sin2α/2cosα=2sinα·cosα/2cosα=sinα;
cos36°+sin18°/cos²18°=
=[(cos²18°-sin²18°)·cos²18°+sin18°]/cos²18°=
=(cos⁴18°-1/4sin²36°+sin18°)/cos²18°