Question

sina+cosa/ корень из 2 cos(pi/4-a)

Answer 1

$frac{sin alpha +cos alpha }{ sqrt{2}*cos( frac{pi}{4}- alpha )} }= frac{sin alpha +cos alpha }{ sqrt{2}*(cos frac{pi}{4}*cos alpha +sin frac{pi}{4}*sin alpha) }= frac{sin alpha +cos alpha }{ sqrt{2}*(sin alpha +cos alpha ) }= frac{1}{ sqrt{2} }$