- 
					 If A, B and C be the angles of a triangle, then put of the following, the incorrect relation is :
- 
                        -  sin A + B = cos C 2 2 
-  cos  A + B   = sin C 2 2 
-  tan  A + B   = sec C 2 2 
-  cot  A + B   = tan C 2 2 
 
-  
Correct Option: C
A + B + C = π
| ⇒ | = | - | 2 | 2 | 2 | 
| ⇒ sin |  |   | |||
| 2 | 
| = sin |  | π | - | C |  | ||
| 2 | 2 | 
| = cos | 2 | 
Similarly,
| cos |  | A + B |   | = sin | C | |
| 2 | 2 | 
| cot |  | A + B |   | = tan | C | |
| 2 | 2 | 
| tan |  | A + B |   | = cot | C | |
| 2 | 2 | 
 
	