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 =