Answer with explanation:
Secant of any angle is inverse of Cosine.
⇒Value of Sec of an angle for various Angles
Sec 0°=1
Sec 30°

Sec 45°

Sec 60°=2
Sec 90°=Not Defined
→→Sec is undefined for , odd multiple of 90°.
That is, Theta

where, k=............-6,-5,-4,-3,-2,-1,0,1,2,3,4.........