9 c0s (pi.x/12) sin (cos -1 (x/2)) Sin alpha=-0.

Please help with these questions

1. log5(5x-2)=1
2. Cos (11pi/6)
3. Sin (-5pi/6)
4. Sec(-3pi/4)
5. cot(-25pi/6)
6. tan(pi/6)
7. tan(pi/4)
8. cosq(x)=3.9 c0s (pi.x/12)
9. sin (cos-1 (x/2))
10. Sin alpha=-0.2757 ,where -90 degrees i less or equal to alpha which is greater or equal to 90degreeed.