Question

По этапно cos (x-п/4)=1/2

Answer 1

x-π/4 = ±π/3+2πn
x = ±π/3+π/4+2πn
x1 = -π/12+2πn
x2 = 7π/12+2πn
n∈Z

Answer 2

$cos (x- frac{pi}{4})= frac{1}{2} \x- frac{pi}{4}= frac{pi}{3} +2pi n, n in Z \x=frac{pi}{3}+ frac{pi}{4}+2pi n, n in Z \x_1= frac{7pi}{12} +2pi n, n in Z \x- frac{pi}{4}= -frac{pi}{3} +2pi n, n in Z \x= frac{pi}{4}-frac{pi}{3}+2pi n, n in Z \x_2= frac{3pi-4pi}{12} +2pi n, n in Z \x_2= -frac{pi}{12} +2pi n, n in Z$