Question

What is an identity

Answer 1

Is this related to trigonometry? :)

Answer 2

An identity is something that hols true for all real number.

Answer 3

holds*

Answer 4

There are many ways of talking about identity.

In basic mathematics we have \(0\) is an additive identity because \(a+0=a\) for any number \(a\). Similarly \(1\) is the multiplicative identity because \(a*1=a\) for every number \(a\).

We also can think of the function \(f(x)=x\) as the identity function because (in the same sense as the other examples) \(f(a)=a\) for every real number \(a\).

There are many other types of Identities so maybe explain a little more so we know what you are looking for.