1)cos(29°) × sin(59°) – sin(31°) × sin(29°)
2)cosa=2/3;3П sinb=1/3;П/2

1)cos(29°) × sin(59°) = 0,7496954135
sin(31°) × sin(29°) = 0,2496954135
0,7496954135 – 0,2496954135 = 0,5
√1-2/3=  ==0.3
√1-1/3=