# Sine and cosine wave

The simplest sine function has the function equation $y=\sin(x)$. The graph is called the **sine wave**.

The simplest cosine function has the function equation $y=\cos(x)$. The graph is called the **cosine wave**.

!

### Remember

To specify the angle $\alpha$ (see unit circle) not in degrees on the coordinate system, it is often converted to **radian**.

$180^\circ\mathrel{\hat=}\pi$

The concrete formula for converting is:

$x=\alpha\cdot\frac{\pi}{180^\circ}$

i

### Properties

- The range $W=[-1,1]$ and the domain $D=\mathbb{R}$ (real numbers)
- The
**amplitude**(maximum deflection) is 1 - The
**periode**(repetition) is $2\pi$