Rozwiąż równanie cosx+cos(x-pi/4)=0. Pomocy

cos(x)+cos(x-π/4)=0 cos(x-π/4)=-cos(x) cos(x-π/4)=cos(π-x)⇒ x-π/4=π-x+2kπ  lub x-π/4=-π+x+2kπ  lub 2x=5π/4+2kπ  lub  sprzecznosc odp x=5π/8+kπ Inny sposob to zamiana na iloczyn cos(x)+cos(x-π/4)=2cos(x-π/8)·cos(π/8) cos(x-π/8)·cos(π/8)=0 cos(x-π/8)=0 x-π/8=π/2+kπ x=5/8π+kπ Pozdr Hans