Question

The volue of sin 18 digre cos 72degre

Answer 1

Step-by-step explanation:

We will be using the trigonometric ratios of complementary angles to solve the given question.

sin (90° - θ) = cos θ

tan (90° - θ) = cot θ

sec (90° - θ) = cosec θ

(i) sin 18°/cos 72°

Since, sin (90° - θ) = cos θ

Here, θ = 72°

sin 18°/cos 72° = sin (90° - 72°)/cos 72°

= cos 72° / cos 72°

= 1