# How do I this equation is not an identity? Write explanation in paragraph form (Siny+Cosy)²=Sin²y+Cos²y

##### 1 Answer

Mar 22, 2018

See Below.

#### Explanation:

An **Identity** is an algebraical expression with variables, where the expression remains true, no matter what the values variables take.

So, Here The expression is

The Left Hand Side, When expanded, is equal to:

But The Right Hand Side is equal to

So, L.H.S

So, This can't be an identity in any cost.