Solve 3cos 2x = 1 for 0 < x < 2pi. Round your answers to the nearest hundredth of a radian.

Question

Solve 3cos 2x = 1 for 0 < x < 2pi. Round your answers to the nearest hundredth of a radian.

Answer 1

3cos 2x = 1 for 0 < x < 2π

cos 2x = 1/3

2x=arccos(1/3)+2π*k, k=0, ±1, ±2, ±3,...

x=(-1/2)arccos[1/3] + π*k

x=(1/2)arccos[1/3] + π*k

arccos(1/3)=1.23 (in radiians)

Now you can select solution(s) from to the interval [0, 2π].