Question

कॉस 15 डिग्री माइनस साइन 15 डिग्री इज इक्वल टू​

Answer 1

Step-by-step explanation:

Solution:

For all values of the angle A we know that, (sin A2 + cos A2)2 = sin2 A2 + cos2 A2 + 2 sin A2 cos A2 = 1 + sin A

Therefore, sin A2 + cos A2 = ± √(1 + sin A), [taking square root on both the sides]

Now, let A = 30° then, A2 = 30°2 = 15° and from the above equation we get,

sin 15° + cos 15° = ± √(1 + sin 30°) ….. (i)

Similarly, for all values of the angle A we know that, (sin A2 - cos A2)2 = sin2 A2 + cos2 A2 - 2 sin A2 cos A2 = 1 - sin A

Therefore, sin A2 - cos A2 = ± √(1 - sin A), [taking square root on both the sides]