równanie
rose: Jak rozwiązać to najprościej cos(2x)=sin(x+45o)
1 maj 17:08
Mila:
cos(2x)=sin(x+45
o)
| √2 | | √2 | |
cos2x−sin2x=sinx* |
| + |
| cosx |
| 2 | | 2 | |
| √2 | |
(cosx−sinx)*(cosx+sinx)− |
| (cosx+sinx)=0 |
| 2 | |
| √2 | |
(cosx+sinx)*(cosx−sinx− |
| )=0 |
| 2 | |
| √2 | |
(cosx+sinx)=0 lub (cosx−sinx− |
| )=0 |
| 2 | |
dalej potrafisz?
1 maj 17:33
róża ma kolce:
sin(x+45o)= sin[90o+(x−45o)]= cos(x−45o)
to
cos(2x)=cos(x−45o)
2x= x−45o+ k*180o v 2x= −x+45o+k*180o , k∊ℤ
v 3x= 45o+k*180o
x= −45o+k*180o v x= 15o+k*60o , k ∊ℤ
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1 maj 18:17