Answer:
0, π
Step-by-step explanation:
cos x sin x = sin x
cos x sin x - sin x = 0
sin x (cos x - 1) = 0
sin x = 0, x = 0, π
cos x - 1 = 0
cos x = 1, x = 0
So answers: 0, π
0
20
Answer: 1. ( 9r - 8 ) x ( r - 2 )
2. ( 5b - 3 ) x ( 5b + 3 )