Use even and odd identities to evaluate trig functions

The video tutorial explains the concept of even functions, focusing on cosine and secant. It describes how even functions remain unchanged when the input value is negated. The tutorial demonstrates calculations involving cosine and secant of negative values, emphasizing the reciprocal relationship between secant and cosine.

What are the properties of even functions as discussed in the text?

Explain how the cosine function behaves when taking the negative of its value.

If cosine of negative T is equal to -1/5, what can you deduce about cosine of T?

What is the relationship between secant and cosine functions?

How do even functions maintain their properties when the input is negated?