1. sec (90o − A) =   tan A   sec A   sin A   cos A   cosec A   Hint Half-n-half Clue   2. cos (90o − A) / sin (90o − A) =   tan A   1   sec (90o − A)   cot A   tan (90o − A)   Half-n-half Clue   3. The value of tan 60o cos 30o − sin 60o tan 30o is   3 / 2   1   2   0   1 / 2   Half-n-half Clue   4. sin2 A − sec2 A + cos2 A + tan2 A =   1   cosec A   cosec 2A   0   cot A   Half-n-half Clue   5. The value of sin2 30o + cos2 30o is   3 / 2   1   0   1 / 4   1 / 2   Half-n-half Clue   6. The value of tan 45o + cos 0 + sin 90o is   1   1 / 2   2   3   0   Half-n-half Clue   7. 1/(1 + cot2 A) + 1/(1 + tan2 A) =   sin2 A   1   cos2 A   0   sin2 A/cos2 A   Half-n-half Clue