Trigonometric ratio of an angle thetaθ is same as that of 2npi+theta2nπ+θ, where nn is an integer. In other words trigonometric ratio of an angle does not change if 2pi2π or its multiple is added to the angle or is subtracted from the angle.
As such, as (5pi)/2=2pi+pi/25π2=2π+π2,trigonometric ratio of (5pi)/25π2 and pi/2π2 are same.
Now sin(pi/2)=1sin(π2)=1, cos(pi/2)=0cos(π2)=0, tan(pi/2)=ootan(π2)=∞, cot(pi/2)=0cot(π2)=0, sec(pi/2)=oosec(π2)=∞ and csc(pi/2)=1csc(π2)=1,
hence sin((5pi)/2)=1sin(5π2)=1, cos((5pi)/2)=0cos(5π2)=0, tan((5pi)/2)=ootan(5π2)=∞, cot((5pi)/2)=0cot(5π2)=0, sec((5pi)/2)=oosec(5π2)=∞ and csc((5pi)/2)=1csc(5π2)=1.