Use cofunction identities and trig identities to find the indicated trig functions

The video tutorial explains how to evaluate the cosine of a negative angle, starting with the cosine of t being -3/4. It highlights the property of cosine as an even function, meaning cosine of t equals cosine of negative t. The tutorial concludes that the cosine of negative t is also -3/4.

How can you express the relationship between cosine of T and cosine of negative T?

What is the significance of the cosine function being equal for T and negative T?