Electrical Systems

Sine and Cosine Values

The curve is  

The Sine or Cosine waves known as Sinusoid are curves with repetitive oscillations with shapes as one can see above.

The values of alternating voltage and Current (AC) varies sinusoidally with time so represented by trigonometric Sine or Cosine curves.

Right Angle Triangle

Sin(θ) = opposite side hypotenuse
Cos(θ) = adjacent side hypotenuse