Question
Solve the equation for the indicated domain.
sec(theta+81 degrees)=2
Theta E[0,360)
sec(theta+81 degrees)=2
Theta E[0,360)
Answers
Reiny
sec(Ø + 81) = 2
cos(Ø + 81) = 1/2
I know cos 60° = 1/2
so Ø+81 = 60 or Ø+81 = 300°
Ø = 60-81 = -21° or Ø = 219°
now the period of cos(Ø+81) = 360°
so adding 360 will give me another answer
so Ø = -21 + 360° = 339°
so in the given domain:
Ø = 219° , 339°
cos(Ø + 81) = 1/2
I know cos 60° = 1/2
so Ø+81 = 60 or Ø+81 = 300°
Ø = 60-81 = -21° or Ø = 219°
now the period of cos(Ø+81) = 360°
so adding 360 will give me another answer
so Ø = -21 + 360° = 339°
so in the given domain:
Ø = 219° , 339°