Processing Math: Done

From Förberedande kurs i matematik 1

Because tanv=sinvcosv, the condition tan v=1 gives sin v= cos v, i.e. we look for angles in the unit circle whose x - and y -coordinates are equal.

After drawing the unit circle and the line y=x, we see that there are two angles which satisfy these conditions, v=4 and v=+4=54