Answer:
Our range is within [0,2π]
We cant exceed that.
tan∆ + 1=0
tan∆= -1
∆=tan-¹(-1)
∆=-45°
Now it has 3 Solutions within the given interval
-45° x π/180 = -π/4
So For the second quadrant... 180-∆ = 180-45 =135°
It is true for tan(135) Which is also equal to -1
135xπ/180 = 3π/4
then
360-45 = 315
This is also true because tan(315)=-1
315° x π/180 = 7π/4
This is where we stop so we dont exceed the given range.
