1. The value of tan 20 × tan 40 × tan 80 is

2. If the angles of a triangle be in the ratio 1 : 4 : 5, then the ratio of the greatest side to the smallest side is

3. The general solution of √3 cos x – sin x = 1 is

4. If tan² θ = 1 – e², then the value of sec θ + tan³ θ × cosec θ is

5. The value of cos 20 + 2sin² 55 – √2 sin65 is

6. If the radius of the circumcircle of an isosceles triangle PQR is equal to PQ ( = PR), then the angle P is

7. If cos a + 2cos b + cos c = 2 then a, b, c are in

8. The value of 4 × sin x × sin(x + π/3) × sin(x + 2π/3) is

9. If tan A – tan B = x and cot B – cot A = y, then the value of cot (A – B) is

10. If tan A – tan B = x and cot B – cot A = y, then the value of cot (A – B) is