Electrical engineering: Sine and cosine come from circles

Sine and cosine can be generated by projecting the tip of a vector onto the y-axis and x-axis as the vector rotates about the origin. 

Electrical engineering

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AC circuit analyisis

If we limit ourselves to input signals shaped like sines or cosines, we can develop a whole AC analysis method to figure out what happens in circuits with changing signals. The methods are far simpler than solving a differential equation.

Topic: Science

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