Question

помогите решить cos4x+cos10x=0

Answer 1

cos4x+10x=0

2cos7xcos(-3x)=0

2cos2xcos3x=0

cos7xcos3x=0

cos7x=0

cos3x=0

X= П/14+кп/7, k€z и П/6+кп/3, k€z