Question

what is mean by cos theta​

Answer 1

Answer:

The right triangle definitions of sine and cosine only apply to acute angles, so a more complete definition is needed. The point where the terminal side intersects the unit circle (x, y) is the basis for this definition. Since the radius (and therefore hypotenuse of the right triangle) is 1, the denominators cosine=adjacent/hypotenuse and sine=opposite/hypotenuse are also 1. Thus, the sine definition is y=sine and x=cosine.

Answer 2

Cos ∅→ trignometic ratio

For cos,

• cos 0° = sin 90° = 1.

• cos 30° = sin 60° = √3/2.

• cos 45° = sin 45° = 1/√2.

• cos 60° = sin 30° = 1/2.

• cos 90° = sin 0° = 0.