If
evaluate:
(i) ![]()
(ii) ![]()
Let us consider a right triangle ABC, right-angled at point B

Cot
= ![]()
=
If BC is 7k, then AB will be 8k, where k is a positive integer.
Applying Pythagoras theorem in ΔABC, we obtain
AC2 = AB2 + BC2
= (8k)2 + (7k)2
= 64k2 + 49k2
= 113k2
AC =
k
Sin
= ![]()
= ![]()
= ![]()
Cos θ = ![]()
= ![]()
= ![]()
(i)
= (1 – sin2 θ)/(1 – cos2 θ)
= 
= 
= 
(ii) Cot2 θ = (cot θ)2
= (
2 = ![]()