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Which quadrant does the given angle 621 degrees lie?

Answer 1

Dylan Arnold

#Q_3#

This was, if my memory serves me correctly, how I determined the Q of any

#theta^o#:

Let q = int ( #theta/90# ) be the quotient from the division

#theta/90#.

If q is even and a multiple of 4, #theta in Q_1#;

otherwise #theta in Q_3#.

If q is odd and the remainder in ( q/4 ) is 1, #theta in Q_2#;

otherwise #theta in Q_4#.

Since int ( 621/90 ) = 6 in this case, 4 is not a multiple of 6, it is even.

So, #621^o in Q_3#.

In addition, although int (711/90) = 7 is odd, it is not a multiple of 3.

#711^o in Q_4#,

Int ( 801/80 )= 8 that is even but a multiple of 4. So, #801^o in Q_1#

Int (891/80)= 9 that is odd but a multiple of 3. So, #891^o in Q_2#

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