Trygonometria
Mat: Wiedzac, ze sin2α =2sinα cosα, oblicz wartosci sumy cos15+cos75.
12 kwi 17:32
M:
8 lut 21:10
Goblin:
| | 15o+75o | | 15o−75o | |
cos15o+cos75o=2cos |
| *cos |
| = |
| | 2 | | 2 | |
| | √2 | | √3 | | √6 | |
=2*cos45o*cos30o=2* |
| * |
| = |
| |
| | 2 | | 2 | | 2 | |
8 lut 23:10
Nicoll:
w treści : " wykorzystując wzór na sin2α"
W= cos15
o+cos75
o |
2
W
2=(cos15
o+sin15
o)
2
| | 3 | |
W2= 1+2sin15ocos15o = 1+sin30o = |
| |
| | 2 | |
8 lut 23:44