Question

please do this question because it is urgent and get brain list answer mark

Answer 1

Step-by-step explanation:

Note : [ I have taken theta as " a " ]

sin a + cos a = ^2cos a

sin a = ^2cos a - cos a

sin a = cos a ( ^2 - 1 )

cos a - sin a = cos a - [ cos a (^2 -1 ) ]

= cos a - ^2cos a + cos a

= 2cos a - ^2cos a

= ^2 cos a ( ^2 - 1 )

= ^2 * cos a ( ^2 - 1 )

= ^2 sin a

Hence proved...

Hope it helps.... Thank you...