Problems
The angle between the vectors
The angle between the vectors
Calculate the angle between two vectors.
Input
Four integers x1
,y1
,x2
,y2
- the coordinates of two nonzero vectors. All values do not exceed 10000 by the absolute value.
Output
Print the value of an undirected angle between vectors with 5 decimal places in the interval [0; π].
Input example #1
2 1 3 5
Output example #1
0.56673