B Tan^-1 to PI Form: Get Help Here

[axer]

Hello, so while i was doing my own revision. When putting tan^-1(1/-√3) i receive the answer as -30. however, (im doing demovoier's theorem) in the revision book it says the answer should be 5π/6 .

Help to brighten me? thanks.

 

[Niladri Dan]

I think you are right because the principal value of arctan lies from -π/2 to π/2...

 

[MAGNIBORO]

Hello, so while i was doing my own revision. When putting tan^-1(1/-√3) i receive the answer as -30. however, (im doing demovoier's theorem) in the revision book it says the answer should be 5π/6 .

Help to brighten me? thanks.

make the calculation again but this time set the calculator in radians =D
if you give the answer -pi/6 don't worry is the same as 5pi/6, because tan(-pi/6)=tan(5pi/6)=1/-√3=-√3/3