trygonometria
ikar: cos4 150 − sin4 150
10 sty 23:42
Bogdan:
a4 − b4 = ... dokończ
10 sty 23:46
xa:
1*cos30=
10 sty 23:46
ikar: czemu cos30 ?
10 sty 23:47
xa:
(cos215o+sin215o)(cos215o−sin215o)=1*cos(2*15o)
10 sty 23:53
Mila:
cos(2x)=cos
2x−sin
2x
| | √3 | |
=(cos2(15)−sin2(15))*(cos2(15)+sin2(15))= cos(2*15)*1=cos(30)= |
| |
| | 2 | |
10 sty 23:53