trygonometria
pk pomocy :): rozwiąż równanie
1) sin2x +tgx = cos(32pi − x)
2) 2sinx + 2cosx − tgx = 1
3) sin2x * tgx + 1 = 52cos(pi2 − x)
13 maj 16:56
pk pomocy :): 1) sin2x +tgx = cos(32pi − x)
2) 2sinx + 2cosx − tgx = 1
3) sin2x * tgx + 1 = 52cos(pi2 − x)
13 maj 17:50
Godzio: 2)
| | sinx | |
2sinx + 2cosx − |
| = 1 /*cosx |
| | cosx | |
2sinxcosx + 2cos
2x − sinx = cosx
2sinxcosx − sinx + 2cos
2x − cosx = 0
sinx(2cosx − 1) + cosx(2cosx − 1) = 0
(2cosx − 1)(sinx+cosx) = 0
| | π | | π | |
x = |
| + 2kπ v x = − |
| + 2kπ |
| | 3 | | 3 | |
cosx = sinx
| | π | | π | |
x = |
| − x + 2kπ v x = −( |
| − x) + 2kπ |
| | 2 | | 2 | |
| | π | | π | |
2x = |
| + 2kπ v x = − |
| + x + 2kπ |
| | 2 | | 2 | |
| | π | | π | |
x = |
| + kπ v |
| = 2kπ + sprzeczność |
| | 4 | | 2 | |
| | π | | π | | π | |
Odp: x = |
| + kπ v x = |
| + 2kπ v x = − |
| + 2kπ |
| | 4 | | 3 | | 3 | |
13 maj 18:02
Godzio: 1)
| | 3 | |
sin2x + tgx = cos( |
| π − x) |
| | 2 | |
| | sinx | |
2sinxcosx + |
| = −sinx /*cosx |
| | cosx | |
2sinxcos
2x + sinx = −sinxcosx
2sinxcos
2x + sinx + sinxcosx = 0
sinx(2cos
2x + cosx + 1) = 0
sinx = 0
x = kπ
2cos
2x +cosx + 1 = 0 −> cosx = t
2t
2 + t + 1 = 0
Δ = −7 < 0
Odp: x = kπ
13 maj 18:22
Godzio: 3)
| | 5 | | π | |
sin2x * tgx + 1 = |
| cos( |
| −x) |
| | 2 | | 2 | |
| | sinx | | 5 | |
2sinxcosx * |
| + 1 = |
| sinx |
| | cosx | | 2 | |
4sin
2x + 2 − 5sinx = 0
sinx = t t ∊ <−1,1>
4t
2 − 5t + 2 = 0
Δ = 25 − 32 = −7 < 0 − brak rozwiązań
13 maj 18:25
Basia: Godzio rozwiąż mi zadania
13 maj 18:32