# Math Help - cot2x=0 trig problem

1. ## cot2x=0 trig problem

How are some of the values for cot2x=0 2x= 90, 270?

I understand that cotx= 1/tanx but I didnt know what to do from there as you can't do 1/0.

Any help would be great
Thanks

2. cot2x=0
1/tan2x=0
cos2x/sin2x=0
cos2x=0
2x=(2n+1)pi/2
x=(2n+1)pi/4
also if tan2x=1/0 then right hand side is not defined.
and the fact is that tan2x is undefined for odd values of pi/2
therefor
2x=(2n+1)pi/2

3. thanks man