The area bounded by the y-axis, y=cosx and y=sinx when $0≤x≤\frac{\pi }{2} $ is :

$\sqrt{2}\, sq.units $ $(2\sqrt{2} + 1) sq.units $ $(\sqrt{2} + 1) sq.units $ $(\sqrt{2} - 1) sq.units $

$(\sqrt{2} - 1) sq.units $