If sin x cos x squareroot 2 sinx A pi then the number 0 S
     If sin x + cos x = squareroot 2 sin(x + A pi), then the number 0  
  
  Solution
sin x + cos x = sqrt 2 sin ( x + A pi )
we can write , sin x + cos x = sqrt 2 * 1/ sqrt 2 ( sin x + cos x)
distributing 1/ sqrt 2
= sqrt 2 ( sin x / sqrt 2 + cos x / sqrt 2 )
1/ sqrt 2 = sin pi/4 , cos pi/4
= sqrt 2 ( sin x cos pi/4 + cos x sin pi/4 )
applying sin ( a+ b ) formula
so,
sin x + cos x = sqrt 2 sin ( x + 1/4 * pi )
hence , A = 1/4

