For a second order system with 0 < ξ < 1, the angle which poles make with negative real axis is

For a second order system with 0 < ξ < 1, the angle which poles make

1.	For a second order system with 0 < ξ < 1, the angle which poles make with negative real axis is
A.	sin¯¹ ξ
B.	cos¯¹ ξ
C.	tan¯¹ ξ
D.	cot¯¹ ξ
Answer» C. tan¯¹ ξ