# Tag Info

As pointed out by @AmyB and @DanielRCollins, an equation is simply a statement that two expressions are equal. @Adam remarks that the equation-identity distinction doesn't seem useful; on the contrary, it is instructive to distinguish an identity from a mere equation: Let $z\in\mathbb C,$ $\;C_n$ denote $\left(z^2-2z\cos\left(\frac{n\pi}9\right)+1\right),$ ...