Question

cos(3x-п/4)=0,7
cos(3x - frac {pi}{4} ) = 0.7cos(3x−4π​)=0.7 

Answer 1

Cos(3x-п/4)=0,7; 3x-п/4 = (+-)arccos0,7 + 2πn, n∈Z; x =( (+-)arccos0,7 + π/4 + 2πn)/3, n∈Z;