Using cosec(90° - θ) = secθ

and cot(90° - θ) = tanθ

we have,

Now, sin(90 - θ) = cos θ and

tan(90 - θ) = cot θ we have

[ Since,

tan²θ - sec²θ = 1

sin²θ + cos²θ = 1

tan 60° = √3]