Mariusz:
sin(4α)=2sin(2α)cos(2α)
sin(4α)=4sin(α)cos(α)(cos
2(α)−sin
2(α))
sin(4α)=4cos(α)sin(α)(1−2sin
2(α))
sin(4α)=4cos(α)(sin(α)−2sin
3(α))
sin(4α)=4(sin(α)cos(α)−2sin
3(α)cos(α))
sin(4α)=4(sin(α)cos(α)−2sin
2(α)(sin(α)cos(α))
tg(α)cos(α)=sin(α)
tg(α)cos
2(α)=sin(α)cos(α)
| | cos2(α) | |
tg(α) |
| =sin(α)cos(α) |
| | cos2(α)+sin2(α) | |
| tg(α) | |
| =sin(α)cos(α) |
| 1+tg2(α) | |
tg(α)cos(α)=sin(α)
tg
2(α)cos
2(α)=sin
2(α)
| | cos2(α) | |
tg2(α) |
| =sin2(α) |
| | cos2(α)+sin2(α) | |
sin(4α)=4(sin(α)cos(α)−2sin
2(α)(sin(α)cos(α))
| | x | | 2x2 | | x | | 24 | |
4( |
| − |
| * |
| )= |
| |
| | 1+x2 | | 1+x2 | | 1+x2 | | 25 | |
| x | | 2x3 | | 6 | |
| − |
| = |
| |
| 1+x2 | | (1+x2)2 | | 25 | |
25x−25x
3=6(1+2x
2+x
4)
6x
4+25x
3+12x
2−25x+6=0 * 24
144x
4+600x
3+288x
2−600x+144=0
(144x
4+600x
3)−(−288x
2+600x−144)=0
(144x
4+600x
3+625x
2)−(337x
2+600x−144)=0
(12x
2+25x)
2−(337x
2+600x−144)=0
| | y | | y2 | |
(12x2+25x+ |
| )2−((12y+337)x2+(25y+600)x+ |
| −144)=0 |
| | 2 | | 4 | |
| | y2 | |
4( |
| −144)(12y+337)−(25y+600)2=0 |
| | 4 | |
(y
2−576)(12y+337)−625(y+24)
2=0
(y+24)(y−24)(12y+337)−625(y+24)
2=0
(y+24)((y−24)(12y+337)−625(y+24))=0
y=−24
| | y | | y2 | |
(12x2+25x+ |
| )2−((12y+337)x2+(25y+600)x+ |
| −144)=0 |
| | 2 | | 4 | |
(12x
2+25x−12)
2−((−288+337)x
2+0x+0)=0
(12x
2+25x−12)
2−49x
2=0
(12x
2+25x−12)
2−(7x)
2=0
((12x
2+25x−12)−7x)((12x
2+25x−12)+7x)=0
(12x
2+18x−12)(12x
2+32x−12)=0
(2x
2+3x−2)(3x
2+8x−3)=0
x
1=−2
x
3=−3