Sec is 1/cos
Cos ranges from 1 to -1
as cos nears zero sec ranges to+- infinity
the 3 multiplier changes the range to start at 3 and -3
range : (-inf,-3] U [3,+inf)
or -3 >= y >= 3
Sec is 1/cos
Cos ranges from 1 to -1
as cos nears zero sec ranges to+- infinity
the 3 multiplier changes the range to start at 3 and -3
range : (-inf,-3] U [3,+inf)
or -3 >= y >= 3