identify function in Trignometry
<MATH> \sin^2 \alpha + \cos^2 \alpha = 1 </MATH> where:
Other illustration : https://twitter.com/mathladyhazel/status/1629667530196303874
The identity function is a derivative from the pythagorean theorem.
It states that the square of the longest side (the hypotenuse, or c in the above diagram) is equal to the sum of the squares of the other two sides. So a² + b² = c²