1. 1/4
2. 4
3. 1/2
4. 2
4
1. 2
2. 3
3. -2
4. -3
-2
1. 1
2. -1
3. 0
4. 2
1
1. -1/2
2. 1/2
3. -3
4. 0
0
1. 1/6
2. 1/9
3. -1/6
4. -1/9
1/9
1. 1/2
2. 1
3. 1
4. none
1/2
1. 0
2. 1
3. 2
4. 1/2
0
1. π
2. π/2
3. π/3
4. π/4
π/2
1. ab/c
2.
3. c/ab
4.