Odpowiedzi

2010-02-07T00:22:17+01:00
(sin20°+cos 20°)²+(sin 20°-cos 20°)²
=sin²20°+2sin20°cos20°+cos ²20°+sin² 20°-2sin20°cos20°+cos ²20°=
=2sin² 20°+2cos ²20°=2(sin² 20°+cos ²20°)=2*1=2


1 - sin 45° 2sin 30°-4cos 60° =
1-√2/2*2*½-4*1/2=1-√2/2-2=-1-√2/2