1) sin7°cos23°+sin23°cos7°+3=?

2) sin60°cos26°+cos64°sin26°-sin30°=?

3) 8sin25°sin65°деленное дробной чертой на cos40°=?

4) tg12°+tg33° деленное дробной чертой на 1-tg12°tg33°

1) ... = sin (7°+23°) + 3 = sin30°+3 = 3,5;

2) ... = sin (64° + 26°) - 1/2 = sin90° - 1/2 = 1-1/2 = 1/2;

3) ... = 8sin25°*sin (90° - 25°) / cos40° = 8sin25°*cos25° / cos40° = 4sin50 °/cos40° =

=4sin (90°-40°) / cos40° = 4cos40°/cos40° = 4;

4) ... = (tq12°+tq33) ° / (1-tq12°*tq33° = tq (12°+33°) = tq45° = 1.