Question

If cosx+sinx=root2,s.t cosx-sinx=root2sinx

Answer 1

Hi ,

Cos x + sinx = √2---( 1 )

Square equation ( 1 ) ,

( cosx +. Sinx )² = ( √2 )²

cos² x + sin² x + 2cosxsinx = 2

1 + 2cosxsinx = 2

2cosxsinx = 2-1

2cosxsinx = 1 ------( 2 )

Now ,

( cosx - sinx )²

= Cos² x + sin² x - 2cosxsinx

= 1 - 1

= 0

Therefore ,

Cosx - since = 0

I hope this helps you.

:)