If A, B and C are the interior angles of a △ABC, show that :

(i) cos $\dfrac{A + B}{2}$ = sin $\dfrac{C}{2}$

(ii) tan $\dfrac{C + A}{2}$ = cot $\dfrac{B}{2}$

The value of $\dfrac{\text{tan 30°}}{\text{cot 60°}}$ is

1. $\dfrac{1}{\sqrt{2}}$

2. $\dfrac{1}{\sqrt{3}}$

3. $\sqrt{3}$

4. 1

The value of tan² 30° - 4 sin² 45° is

1. 1

2. $\dfrac{7}{3}$

3. $-\dfrac{5}{3}$

4. $-\dfrac{11}{3}$

If A = 30°, then the value of 2 sin A cos A is

1. $\dfrac{1}{\sqrt{2}}$

2. $\dfrac{\sqrt{3}}{2}$

3. $\dfrac{1}{2}$

4. 1