Given that cot (13pi/14)= tan z, find angle z.
So I used cot x=tan(pi/2-x), and I got the answer -3pi/7, but the answer says it's positive, so I am confused.
Thanks in advance!
Yes, it is correct and tg must be negative because cotangent is in II. Quadrant. Maybe in your book there is positive solution because if you add 2pi to -3pi/7 you get the same angle 2pi+(-3pi/7)=11pi/7 but in positive direction.