133) (2Cos²68° - 1) / (2Cos113°* Sin67°) = Cos136° / [2cos(180°- 67°)*Sin67°= Cos136° / (- 2cos67°*Sin67°) = Cos136° / - Sin 134 =
= Cos(90° + 46°) / - Sin (180° - 46°) = - Sin46° / - Sin46° = 1
146) Разделим почленно на Cosa:
(8Sina/Cosa - 9Cosa/Cosa) / ( 6Cosa/Cosa - 7Sina/Cosa) =
= (8tga - 9) / (6 - tga) = (8*2 - 9) / (6 - 2) = 7/4 = 1,75
148) Опять разделим почленно на Cosa:
(Sina/Cosa + 2Cosa/Cosa) / (4Cosa/Cosa - 3Sina/Cosa = 5
(tga + 2) / (4 - 3tga) = 5
tga + 2 - 20 + 15tga = 0
16tga = 18
tga = 18/16 = 1,125