2sinacosa=sin2a
(50sin19°*cos19°)/sin38° .=25*2sin19°*cos19°)/sin38°=25sin(2*19)/sin38=25sin38/sin38=25
2sinacosa=sin2a
(50sin19°*cos19°)/sin38° .=25*2sin19°*cos19°)/sin38°=25sin(2*19)/sin38=25sin38/sin38=25