Răspuns:
Explicație pas cu pas:
(sin x/2+cos x/2)²=sin²x/2+cos² x/2+2sinx/2×cosx/2=1+sinx
sin x+√1-sin²x=0.2 1-sin²x=sin²x+0.04+0,2sinx
notam sin x=t 2 t²+0,2t-0,96=0 200t²+20t-96=0 :4
50t²+5t-24=0 t1,2=-5±√25+1200/100=-5±35/100
t1=0,3 sin x/2+cos x/2=√1+0,3=√1,3
t2=-0,4 nu convine
