Which term of the A.P. 27, 24, 21, 18, …… is the first negative term ?

1. 10th

2. 11th

3. 12th

4. 9th

For the following distribution, the upper quartile is :

1. 35

2. 30

3. 45

4. 40

Prove that : (sin A + sec A)² + (cos A + cosec A)² = (1 + sec A. cosec A)².