Question

Помогите номер 364 Упростите

Answer 1

а) sin2a/sina = 2sinacosa/sina = 2cosa

б) sin2a/2cosa = 2sinacosa/2cosa = sina

в) sin2a /(cos²a - sin²a) = sin2a / cos2a = tg 2a

г) cos2a + sin²a = cos²a - sin²a + sin²a  = cos²a

д) sin40° / 2cos20° = 2sin20°cos20° / 2cos20° = sin20°

е) sin100° / 2cos50° = 2sin50°cos50° / 2cos50° = sin50°

ж) (cos36° + sin²18°)/cos18° = (cos²18° - sin²18° + sin²18°)/cos²18° = cos²18°/cos²18° = 1

з) sina / (2sin²(a/2)) = (2sin(a/2)cos(a/2))/(2sin²(a/2)) = cos(a/2)/sin(a/2) = ctg (a/2)

Answer 2

Спасибки