2 Evaluate 
cos
cos
cos
sin
–sin
–sin
cos
0
sin
cos
sin
sin
cos
α
β
α
β
α
β
β
α
β
α
β
α 3 If A–1 = 
(
)
1
3
1
1
1
2
2
15
6
5 and B
1
3
0
, find AB
5
2
2
0
2
1
–
–
–
–
–
–
–
–








=












4