Sinx = - 40/41 (3 четверть)

Cosx = - 21/29. (2 четверть)

Sin (п/9 - 6x) = - ✓3/2

1

sinx=-40/41

cosx=-√ (1-sin²x) = - √ (1-1600/1681) = - √ (81/1681) = - 9/41

tga=sina/cosa=-40/41: (-9/41) = 40/41*41/9=40/9

ctga=1/tga=1:40/9=9/40

2

cosx=-21/29

sina=√ (1-cos²x) = √1-441/841) = √ (400/841) = 20/29

tga=sina/cosa=20/29: (-21/29) = - 20/29*29/21=20/21

ctga=1/tga=1:20/21=21/20

3

sin (π/9-6x) = cos (6x+7π/18)

cos (6x+7π/18) = - √3/2

6x+7π/18=-5π/6+2πk U 6x+7π/18=5π/6+2πk

6x=-5π/6-7π/18+2πk U 6x=5π/6-7π/18+2πk

6x=11π/9+2πk U 6x=4π/9+2πk

x=11π/54+πl/3 U x=π/27+πk/3, k∈z