The equation for the unit circle...........if u add straight across....................adding  exponents................................u get 5.............................in one way...........the other........6...............5 and 6..............2 + 3 = 5...................2 * 3 = 6.............................1 has an exponent of 1........any number does............. 6 is understood as 6 to the one.............just one 6 is 6..............


PythagorasPythagoras' Theorem says that for a right angled triangle, the square of the long side equals the sum of the squares of the other two sides:

x² + y² = 1²

But 1² is just 1, so:

x² + y² = 1
(the equation of the unit circle)

Also, since x=cos and y=sin, we get:

(cos(θ))² + (sin(θ))² = 1

a useful "identity"