For acute angles α and β, if α > β, then :

A : cos α > cos β

B : tan α > tan β

C : sin α > sin β

D : cot α > cot β

Which of the above statement/statements is/are true :

1. A and B

2. B and C

3. C and D

4. D and A

If M = x cos A + y sin A and N = x sin A - y cos A, then M² + N² is :

1. x² - y²

2. y² - x²

3. x² + y²

4. (x + y)²

If sin 2x = 2 sin 45° cos 45°; the value of x is :

1. 45°

2. 90°

3. 30°

4. 60°