Two functions f(x) and g(x) are identically equal if, for every value of x in their domains
f(x)=g(x).
The equation representing this is called an identity.
It is often necessary to establish whether or not an equation involving two trigonometric equations is an identity.
To establish an identity, choose one side of the given equation and manipulate it using known identities until it has been transformed into the other side, or until it cannot be manipulated further.
Quotient Identities
Examples
Show that
Explanation
Even-Odd Identities
Reciprocal Identities
Pythagorean Identities
Examples
Show that
Explanation
Try these exercises:
Verify the identities.
Answers to questions
