(sin60+cos60)(sin60-cos60)

Odpowiedź :

(sin60+cos60)(sin60-cos60)=sin²60-cos²60=(√3/2)²-(1/2)²=
=3/4-1/4=2/4=1/2=0,5
sin60=√3 /2
cos60=1/2
korzystamy ze wzoru: a²-b²=(a-b)*(a+b)

(sin60)²-(cos60)² = (√3/2)²-(½)² = ¾-¼ = ½
(sin60+cos60)(sin60-cos60) =(√3/2+1/2)(√3/2+1/2)=(√3/2)²-(1/2)² =3/4-1/4=2/4=1/2