3)+What+are+Identities?

An identity is an equation which is **true for any value of the variable**. Also, it is a relation which is tautologically true. This is usually taken to mean something that is true by definition, either directly by the definition, or as a consequence of it.



**** Algebraic Identities ****
Previously in algebra, we learnt about several identities that are used for us to solve equations easier,

Such as:

and

This identities can be used even if the coefficients are different. As long as the it posesses the following, it is a function.

As you can see, Algebraic Identities are identities that include alebraic functions.

On the other hand, Trigonometric Identities are therefore **identities that include trigonometric functions**. *

//*Trigonometric functions are functions such as sine, cosine, tangent, etc.//

** Purpose of Identities **
Trigonometric Identities are extremely helpful, as in calculation, we may replace either member of the identity with the other. We use a trigonometric identity to give an expression/equation a more convenient form.

Just like with algebraic identities and algebraic equations, trigonometric identities are of central importance in calculus. This would greatly aid in solving future problems faster.