If minimum value of (sin−1x)2+(cos−1x)2 is π2kthen the value of K is
4
1
8
10
(sin−1x)2+(cos−1x)2=(sin−1x)2+(π2−sin−1x)2
=2(sin−1x)2−πsin−1x+π24
Its minimum value is 4.2.π24−π28=π28